INTRODUCTION
The following is intended to provide a general introduction for those interested in building a silent HTPC..
The Guide is currently in draft form. Feedback is welcome via PM and discussion in the thread.
INDEX
GENERAL PRINCIPLES
The characteristic that differentiates an HTPC from other computer builds is the quest for quiet (preferably silent) operation. There’s nothing more annoying than building a new PC only to find your favourite movie or piece of music accompanied by the hum of fan noise or the repetitive clicking of hard drives. This means HTPC builders are selective about their choice of components. The following are some general principles to consider when selecting parts and putting them together to make a quiet HTPC.
The main element inside a HTPC case that determines noise is heat. The more heat there is, the harder the CPU, case, and power supply fans need to work to dissipate it. This increase in fan-RPM is what causes most of the noise.
CPU Selection
TDP or Thermal Design Power is an indicator of how much power the CPU uses to run, and also of how much heat needs to be dissipated in order for the CPU to maintain a safe operating temperature. Usually, for each line of CPU’s there is some positive relationship between the processing power the CPU is capable of, and the amount of power it needs to run. Generally, more powerful CPU’s in a given series use more power and create more heat.
The choice of CPU in an HTPC will depend entirely on what the machine will need to do. The CPU can be a good starting point for working on a build, as the rest of the components will follow from this choice.
If the machine is just for playing HD video and/or recording TV, then low-power CPU’s are preferable, because of their lesser heat generation. The main media-related task which can utilise higher CPU power is video encoding (taking a file in one format, for example a Blue-Ray disk, and changing it to another format, for example an MKV file). The faster the CPU, and the more cores it has, the quicker the machine will be able to output a re-encoded file from an original file in another format. Gaming will make use of higher end CPU’s. Some users opt to use a separate machine for CPU-intensive tasks, so that they can build an HTPC with a low TDP CPU. Others prefer an ‘all in one’ solution that has enough processing power to do everything.
Summary:
If the machine is for playing and recording media, there is no real advantage to using a high end CPU. It will have literally zero impact on video or audio quality over a lower end current-gen CPU. If the machine is to be used for additional tasks, and those tasks are cpu intensive, there are then benefits to looking higher up the CPU price/performance range. In terms of cores, there is no specific benefit at present to run more than 2 for media recording and playback. More cores do, however, come into play if the machine is to be used for intensive tasks such as video encoding.
CPU cooling
After-Market Heatsink Fans
Stock CPU coolers will provide adequate cooling at stock speeds. Noise levels vary, depending on the TDP and brand of the CPU and its heatsink/fan (HSF) configuration.
After-market CPU coolers use larger surface area, bigger fans and better quality components to cool more efficiently. There is a huge range of after-market HSF configurations. Most models are designed to improve overclocking performance (generally not relevant to building quiet HTPC as it increases heat), and there is considerable variance in noise levels between models. The quieter ones offer obvious noise-lessening benefits over a lot of stock cooling.
If seeking an after-market CPU cooler, consider your case clearance. This is the amount of space from the top of the seated CPU to the lid of the case. Also check the height of your ram, as some coolers sit quite low to the motherboard.
There are a variety of mounting mechanisms, but they all fall into two basic categories – those with, and those without, a backplate. Backplated HSF’s require the removal of an installed motherboard in order to mount the backplate to its underside. Non-backplated HSF’s can generally be attached to the motherboard without removing it from the case. There is a clear advantage to using a non-backplated HS if the machine has already been built, as it may eliminate the need to have to remove the motherboard for its installation.
Look for something with a large, efficient fan.
Passive Cooling
Passive CPU cooling means running the heatsink on the CPU without a fan. This can be achieved by using an appropriate after-market heatsink on the CPU and providing airflow via a source such as a case fan. For example, Antec NSK2480 and Fusion Remote cases have a 120mm case fan right next to the CPU. In this instance, a passive heatsink can be used as there is ample airflow from the 120mm fan. Not all cases are suited to this type of CPU cooling and options will depend on the size and proximity of case fans to the CPU. Be very careful using a heatsinc that is not explicitly suited for passive operation. Passive cooling is unlikely to work with stock heatsinks.
SETTING UP AND TESTING (once you have your HTPC)
Its important to check your CPU cooling is working correctly after installing a new HSF. If the heatsinc is not installed correctly and too much heat is generated, it can result in fried hardware.
To check CPU temperatures, use monitoring software and max out CPU by running maths that will drive it at maximum heat.
Suggested software:
Monitor temps
-Hwmonitor
or
-Speedfan
Torture test CPU @ max heat
-Prime95
Testing Method
Before you begin, be sure to obtain the correct safe operating temp range for your particular model of CPU from a reliable source (IE, Intel, AMD). Start the PC and check the temps before starting any applications that will cause CPU stress. Safe temperature ranges differ between models of CPU, so Once you can see that the CPU is running safely within this range, start Prime95. Keep a close eye on temps to ensure they don’t go over the safe range. The temperature can climb very quickly, so monitor carefully, especially for the first 5-10 minutes. If they remain in a safe range, continue the test until the temperatures level out and have been running continually for some time (1-2 hours). Make sure you continue to check back regularly as it’s easy to fry hardware that is not properly cooled. Ambient temperatures do affect CPU temps, so if you are testing on a cold day in a room that can get hot, ensure there is a margin allowed for additional heat.
Undervolting
One way of lowering a CPU's temperature is to lower the amount of power supplied to it. In the same way as increasing voltage can contribute to overclocking potential, undervolting can also be an asset in cool running of a cpu. The difference here is that undervolting does not affect CPU performance. Its quite possible to lessen power to the CPU (thereby reducing heat) and retain stock clock speed. This is achieved in one of two ways, either via BIOS settings, or via software.
To undervolt, start with the lowest voltage reduction, start the machine, and run something that will max out the CPU (ie Prime95). Once you have ascertained it is stable, repeat the process with the next lowest setting and so on, until you hit an unstable voltage, then increase to the previous stable increment. Dont be afraid of harming your CPU - this is not risky as long as you have set the CPU up properly to start with and know that your cooling system is working properly. If using BIOS, and for any reason find your machine wont start, just do a jumper reset to factory defaults. (Most modern motherboards will auto-compensate for incorrect voltage settings and this will not be necessary).
PSU
The power supply is an important component choice inasmuch as it will determine how much energy is wasted (via its efficiency), how much heat is contributed inside the case, and also, how much noise it makes.
Overhead
Power supplies are generally most efficient between 50 and 75% load. They also run cooler at lower loading than when they are being pushed to their capacity. For these reasons, there are some benefits to selecting a power supply which is rated above the energy consumption of the machine. This overhead can also be beneficial for providing scope for future upgrades, particularly if adding a dedicated GPU, or using a more powerful one is a prospect.
Consider a PSU rated at approximately 200% of power consumption. This does not mean the machine needs power availability at double its actual power usage. This formula will, however, provide a PSU that will be cool, quiet and efficient, by running at an optimal load. It also provides protection against lost efficiency which will occur over time from capacitor ageing.
Beware also of selecting a PSU which is too powerful, as efficiency can drop off significantly @ < 20% load. While this won't necessarily affect noise, it will affect power consumption. 80plus certification does not measure PSU efficiency under 20%, so the certification (and its indication of efficiency) does not apply if your PSU is too big for your build.
How to calculate PSU size
There are a number of PSU calculators available online. One such example is HERE. If you are considering adding a dedicated GPU in future (or several if you are a Gamer), it would be wise to factor these parts into your initial calculations.
Modular design
Modular PSU's use a cabling system whereby rails are plugged in as needed, as opposed to a non-modular system where all rails are ‘fixed’ to the PSU. The advantages to using a modular PSU is the reduction of cable clutter and slightly improved air-flow within the case.
80Plus certification
80Plus is a program that originated in North America which provides certification to power supply manufacturers that indicate a standard of 80% efficiency or higher. This certification has made considerably impact on the PSU industry, with manufacturers building to attain the certification. Generally speaking 80plus certification is a reasonable base indicator of build quality – higher efficiency means that the components inside the PSU are likely to last longer, and that higher quality parts are used in order for the PSU to run efficiently. 80Plus has four categories:
Passive and Semi-Passive designs
Passive cooling refers to a design which is cooled entirely without the use of a fan. Semi-passive means that the PSU will only use a fan above a certain power draw, (for example, 50%). These models tend to cost more than their air-cooled counterparts, but provide one less source of noise in the overall design of the machine.
GPU’s and power consumption
A dedicated graphics card (GPU) is an important aspect in selecting a power supply. Generally speaking, a mid-range GPU will state a minimum 400-450w power supply as a requirement. Low-end GPU’s may have a stated requirement of 300-350w. This does not mean that they consume that amount of power, but is an indication provided by manufacturers which takes into account most build configurations and their base power consumption, then ensures an additional margin of power is available to ensure the GPU will function well.
Summary:
Look for an 80plus rated PSU with low noise output. Ensure you calculate PSU size carefully against your proposed build and factor in upgrades, particularly the addition of a GPU. Passive and semi-passive designs are preferable as they contribute little or no noise.
PSU: Recommended:
Budget
Corsair CX400
Antec Earthwatts 380w
Mid Range
Enermax EMG500AWT
Passive
Seasonic X400
PicoPSU
150w version available! - low-power machines only
RAM
At the time of writing there are probably more RAM choices simultaneously available than there have ever been for HTPC builders. Starting at 667mhz and going up to 1600mhz or higher, and also in two different flavours – DDR2 and DDR3, and with a large range of timings aimed at stock speeds and also allowing scope for overclocking. Generally speaking, your choice of ram will not make a great deal of difference to media playback quality. In other words, its not necessary to use high-end ram for the purposes of running HTPC software to play and record media. Faster RAM may be useful to builders who are looking at an ‘all in one’ solution, particularly if the machine will be used for gaming or for video editing, or for other RAM-intensive tasks.
2GB vs 4GB
There is some debate currently about how much RAM to use in a dedicated HTPC. Generally speaking, media recording/playback and menu navigation are not ram-intensive tasks. Many builders find that 2GB is more than adequate. If the machine is to be used for heavy multitasking jobs, like running virtual machines, or video editing, extra RAM will be an asset and will be utilised. 32-bit OS’s won’t use much more than 3gb of physical RAM. 64-bit OS’s can utilise far more. Fortunately, RAM is a relatively simple and inexpensive component to add if extra is required. For HTPC tasks at the time of writing this thread, 2-4gb is ample. 6+ GB is unlikely to provide any significant benefit, although this may well change with time, depending on the state of software and OS development.
DDR2 or DDR3
In real world tests there is not an enormous amount of performance difference between the two designs. Motherboard choice will be a determinant of which type to use, as DDR3 ram will not fit DDR2 boards, and vice-versa. There is currently no significant performance deficit for a machine that uses similarly spec'd DDR2 in terms of HTPC tasks. Obviously the benefit to DDR3 is slightly improved general performance and currency/positive resale value.
CASE AND CASE FANS
CASES: GENERAL FEATURES
Cabinet – IMPORTANT!!
The size of the available area in a entertainment unit/cabinet will have implications for the choice of case. Its essential to select a case that will have ample room for air-flow on all sides once its been installed in the cabinet. The rear of the space should ideally be open, to allow exhaust from the power supply and rear case fan/s. The space on each side and above should also be 30-40mm or more to allow for adequate heat dispersal. It is very important that these aspects are taken into account. If confined in a small space, the machine will run hot, or in the worst cases, overheat.
Form-Factor
There are three common form factors used for HTPC builds. In order of size, smallest to largest - Mini ITX, Micro ATX and ATX – with Micro ATX being the most common. Most ATX cases will accommodate the smaller mITX and mATX boards. Most mATX cases will accommodate mITX boards. The advantage to larger boards is more room for expansion. Larger boards require larger cases. If you have limited space for your HTPC, the form factor may be a good place to start. More discussion below in MOTHERBOARD section.
VFD or not VFD?
Many cases offer a front display. These begin at the simple 2-line LED style iMON as seen on cases like the Silverstone LC20B-M and go up to mini-TV style touch-screens as seen on the originAE S21T. I won't discuss pros and cons in any length here, as this is a stylistic choice. Opinions differ as to the usefulness of front displays. Suffice to say that compatibility should be checked in the Forum to ensure the display will function properly with MP.
IR Receiver
Built-in IR offers the ability to point a remote control at the case and have it respond to the commands. Having the receiver built in circumvents the need to run an external IR through a USB cable.
Storage Expansion
An important consideration if you are planning on using your HTPC as a storage device for a large media collection is its capacity to hold additional hard drives. A general rule of thumb is that the form-factor of the case will determine the scope space for additional drives.
Internal And External Drive Bays
In case specifications, the drive bays are referred to as 'internal' and 'external'. External means the bay is accessible from the exterior of the machine. 5.25" bays are usually external. 3'5" bays come in both flavours - external 3.5" bays commonly are used for things like card-readers, and sometimes fan controllers.
Bay Adapters
If short on 3.5" bays for hard drive installation, a 5.25" bay can be used with a caddy which sits on each side of the drive to bridge the space between the sides of the drive and the sides of the bay. SSD's are usually sold with such a caddy so they can be installed in a 3.5" bay. 4x 2.5" to 5.25" adapters are also available (fit 4x 2.5" drives in a 5.25" bay). When considering a case, don’t be put off by the initial specs as it may be possible to fit your preferred drive configuration by using adapters.
Low-Profile Cases: considerations
Low profile cases are popular for HTPC's because of their capacity to fit into small spaces and their clean aesthetic integration into a population of AV gear. There are some implications for the use of low-profile cases that are important to consider:
CPU cooler
The height of after-market CPU coolers is more limited in lowpro cases than full height cases. This can have implications for the amount of noise the cooler makes. The extent of this effect will depend on the TDP of the CPU and the load that it is under, and on the ambient temperature inside the case and its effect on the CPU temperature.
Expansion / video cards
Low-profile cases require low-profile cards. With many expansion cards this is not an issue, but it does pose implications for the choices of video card available, as not all models are available in low-profile. If you have a particular kind of video card in mind when building your machine, it would be worth checking to make sure it will fit. The same maxim applies to tuner and other expansion cards - check that the model you want to use is available in lowpro first
For more information on video cards see the VIDEO CARD section, below. CASES: COOLING
The case's capacity to provide good airflow to all components is an essential aspect of quiet operation.
Fan speed
Fan speed is affected by the amount of power sent to the fan. This can be affected in a number of ways:
1. Fan choice and fixed RPM
Fans are available at various ratings, from 500rpm to 2000rpm. If not using a fan speed controller, the base RPM design will provide some indication of how loud the fan will be at fixed voltage, and of how much air its capable of moving.
2. Analogue speed controller
Analogue speed controllers are a popular choice and feature one or more analogue dials, each of which controls available voltage to a fan. By turning the dial, fan speed can be increased or decreased. The upside of this type of control is the extent of fine control over fan speed they provide. The downside is that they take up a 5.25” or a 3.25” drive bay and create some cable clutter inside the case.
3. In-line resistor
A resistor lowers voltage availability to the fan by sitting in-line between the fan and its power source. Many quality after-market fans are supplied with either one or two resistors, which allows for modular control of fan speed. Resistors of this type have a female and male plug and simply attach in-line.
4. Chipset/motherboard control
Achieved by attaching a fan with a speed controller wire additional to its + and – wires to a compatible fan header on the motherboard.
5. Sotware control
Can be achieved with software like Speedfan. The degree of success achieved will depend on the chipset compatibility of the motherboard with the software, and on the Users ability to correctly utilise the features of the software.
CFM, dBA And Choosing A Fan
‘Cubic Feet Per Minute’ (CFM) refers to how much air a fan can push at a given speed over time. dBA refers to decibel pressure, or audibility to the human ear. There’s generally a positive relationship between CFM and dBA (more air being shifted = more noise).
When picking a case fan, look for something that has the best air flow for the lowest noise level. Some case fan manufacturers cite life expectancy in terms of hours of use (i.e. max 130,000hrs). This figure can also act as a good general indication of the build quality of the fan.
PSU Can Be Implemented As A Case Fan
PSU’s with a 120mm top fan can be used to extract hot air from the case. Some cases allow for upside-down mounting, with the 120mm fan extracting from inside the case, rather from outside it. Given that the PSU fan will be running anyway, its can be efficient to experiment with utilising it for heat exhaust. The downside is that if you have some very hot components running in the case (i.e. high performance hard drives, or a high-end video card) you will be introducing hot air into the PSU, which could have implications for its efficiency and life-expectancy. Obviously the decision to do this or not will depend on your component choices and on existing heat of PSU and on the load it is working under.
STORAGE
SSD or not SSD?
SSD’s seem to be the current flavour of the month for many PC builds. Fast SATA SSD’s offer read/write speeds of up to 270 MB/s, which is more than double the speed of most fast HDD’s. Fast PCI-E SSD’s offer speeds up to 700-800mb/s (eek!).
PROS:
Extremely fast data transfer speeds compared to most spinning disks.
PC’s boot a lot faster
Programs installed on the SSD load more quickly
Generate very little heat
Low energy consumption
Silent
CONS:
Very expensive
Limited storage
Performance degrades over time. See TRIM
SSD’s offer some nice benefits to HTPC users, but add a premium to the price of a new build. If you can afford it, there is no reason to ‘not’ have one (ie no significant negatives). However the actual benefits will depend on how you use your HTPC. HTPC’s generally aren’t booted very often – with most users preferring to use sleep mode (s3/s4) when the machine is not in use. So, the decision to buy one might relate to a question like “how quickly do you actually need your favourite media centre application to load”?
Hard Drives
Fast (10,000rpm) hard drives generate quite a bit of heat, and can be noisy. More drives installed together in the same case equates to more heat generation. Compared with performance and standard 7200rpm drives, ‘Green’ HDD’s consume little power, run cooler, and make very little noise. They are a good choice for HTPC builders. Green drives which typically run at 5400rpm are more than capable of recording multiple television programs simultaneously.
This is not to say that fast HDD’s cant be used in an HTPC - and builders with gaming in mind would be wise to consider their options here, particularly in the 7200 RPM range, but that there are compromises to be considered with faster, high-performance models.
For more information on Drive surface temperature and sound levels, see HERE
2.5” hard drives are quieter than their 3.5” counterparts – so a good budget option if seeking to build a silent client machine without the expense of an SSD may be to go this route. There is a slight size
rice premium for 2.5” drives over their 3.5” counterparts, but not to the same extent as current SSD prices.
Some HTPC users opt to have a two HDD configuration, where one HDD is used as a dedicated operating system / program drive [typically small in size, <320GB], and the other drive is for media storage[>1TB]. The main benefit of this setup is that it is very easy to upgrade the storage capacity without having to go through cloning a HDD or reinstalling the operating software.
Storage: Local or network?
There are two basic storage configurations to consider for an HTPC. The first is to store media in the case of the HTPC itself. The second option is to use a server and client, with the media stored in a server machine and accessed through client HTPC(s) via LAN or wireless network. The decision as to which configuration is preferable will depend on the size of the HTPC case, how many hard disks it can hold, and how much media needs to be stored.
MOTHERBOARD, On-Board and On-CPU Graphics
On-Board Graphics
In recent years the need to use a dedicated video card has lessened with the release of a number of motherboard chipsets that are capable of HD playback. Perhaps the main differentiating point between these chipsets for HTPC users, is the difference in their ability to pass multi channel audio through HDMI
Examples:
There is more information in the Forum regarding on-board graphics/CPU configurations. The basic advantage is lesser power consumption, lower cost, and a free pci-e slot. The disadvantage is that on-board graphics are less powerful and can be limited in reproduction of some HD content (specifically 1080i if paired with an inadequate CPU). At the time of writing, no on-board graphics support audio bitstreaming.
On-CPU graphics
The current generation of Intel Clarkdale CPU’s have a GPU built in. This is a relatively new development in CPU/Motherboard technology, and is possibly the way that CPU technology will head in the near future. The built-in GPU on the Clarkdales has produced some solid benchmark results compared to the range of available on-board chipsets. They also support audio bitstreaming, which is a significant comparitive benefit at this time for Audiophiles. At the time of writing this thread, initial reception was positive, although there have been some mixed reports about their ability to accurately output at 24p.
GRAPHICS CARDS
Passively cooled GPUs are popular in HTPCs because they contribute zero noise. The current state of play is that Radeon 5 series is the only market contender that offers audio bitstreaming. For this reason they are very popular among HTPC builders.
For those using their PC to watch and record TV, there are benefits to using a card that can manage vector adaptive de-interlacing with edge enhancement. For more information on VAD, see THIS thread.
If not requiring de-interlacing of 1080i material, a relatively modest GPU is perfectly adequate for HD playback. My recommendation would be a (2xx series or a 9xxx series nVidia), or a (4/5 series Radeon). Any of these cards will offer hardware accelerated HD playback.
Please see the section PSU, above, for information on power utilisation of dedicated graphics cards, and their relationship to PSU choice.
MORE INFORMATION
The following is intended to provide a general introduction for those interested in building a silent HTPC..
The Guide is currently in draft form. Feedback is welcome via PM and discussion in the thread.
INDEX
General Principles
CPU Selection
CPU Cooling
-After-Market Heatsink Fans
-Passive Cooling
-Testing
-Suggested Software
-Testing Method
-Undervolting
PSU
-Overhead
-How to Calculate PSU Size
-Modular design
-80Plus certification
-Passive and semi-passive designs
GPUs and power consumption
RAMStorage
-On-Board
-On-CPU
Graphics Cards
More Information
CPU Selection
CPU Cooling
-After-Market Heatsink Fans
-Passive Cooling
-Testing
-Suggested Software
-Testing Method
-Undervolting
PSU
-Overhead
-How to Calculate PSU Size
-Modular design
-80Plus certification
-Passive and semi-passive designs
GPUs and power consumption
-2GB vs 4GB
-DDR2 or DDR3
Case and Case Fans-DDR2 or DDR3
-Cases: General Features
--Cabinet
--Form-Factor
--VFD or not VFD
--IR Receiver
--Storage Expansion
--Internal and External Drive Bays
--Bay Adaptors
--Low-Profile Cases: Considerations
--Form-Factor
--VFD or not VFD
--IR Receiver
--Storage Expansion
--Internal and External Drive Bays
--Bay Adaptors
--Low-Profile Cases: Considerations
--CPU Cooler
--Expansion / Video Cards
--Expansion / Video Cards
-Cases: Cooling
--Fan Speed
--CFM, dBA and Choosing a Fan
--PSU can be implemented as a case fan
--CFM, dBA and Choosing a Fan
--PSU can be implemented as a case fan
-SSD or Not SSD?
-Hard Drives
-Storage: Local or Network
Motherboard, On-Board Graphics and On-CPU Graphics-Hard Drives
-Storage: Local or Network
-On-Board
-On-CPU
Graphics Cards
More Information
-HTPC Builds
-Hardware: General
-Cases
-Fans/Cooling
-PSU
-Forums
-Hardware: General
-Cases
-Fans/Cooling
-PSU
-Forums
GENERAL PRINCIPLES
The characteristic that differentiates an HTPC from other computer builds is the quest for quiet (preferably silent) operation. There’s nothing more annoying than building a new PC only to find your favourite movie or piece of music accompanied by the hum of fan noise or the repetitive clicking of hard drives. This means HTPC builders are selective about their choice of components. The following are some general principles to consider when selecting parts and putting them together to make a quiet HTPC.
Low heat = low fan rpm = quiet computer.
The main element inside a HTPC case that determines noise is heat. The more heat there is, the harder the CPU, case, and power supply fans need to work to dissipate it. This increase in fan-RPM is what causes most of the noise.
CPU Selection
TDP or Thermal Design Power is an indicator of how much power the CPU uses to run, and also of how much heat needs to be dissipated in order for the CPU to maintain a safe operating temperature. Usually, for each line of CPU’s there is some positive relationship between the processing power the CPU is capable of, and the amount of power it needs to run. Generally, more powerful CPU’s in a given series use more power and create more heat.
The choice of CPU in an HTPC will depend entirely on what the machine will need to do. The CPU can be a good starting point for working on a build, as the rest of the components will follow from this choice.
If the machine is just for playing HD video and/or recording TV, then low-power CPU’s are preferable, because of their lesser heat generation. The main media-related task which can utilise higher CPU power is video encoding (taking a file in one format, for example a Blue-Ray disk, and changing it to another format, for example an MKV file). The faster the CPU, and the more cores it has, the quicker the machine will be able to output a re-encoded file from an original file in another format. Gaming will make use of higher end CPU’s. Some users opt to use a separate machine for CPU-intensive tasks, so that they can build an HTPC with a low TDP CPU. Others prefer an ‘all in one’ solution that has enough processing power to do everything.
Examples
Summary:
If the machine is for playing and recording media, there is no real advantage to using a high end CPU. It will have literally zero impact on video or audio quality over a lower end current-gen CPU. If the machine is to be used for additional tasks, and those tasks are cpu intensive, there are then benefits to looking higher up the CPU price/performance range. In terms of cores, there is no specific benefit at present to run more than 2 for media recording and playback. More cores do, however, come into play if the machine is to be used for intensive tasks such as video encoding.
CPU cooling
After-Market Heatsink Fans
Stock CPU coolers will provide adequate cooling at stock speeds. Noise levels vary, depending on the TDP and brand of the CPU and its heatsink/fan (HSF) configuration.
After-market CPU coolers use larger surface area, bigger fans and better quality components to cool more efficiently. There is a huge range of after-market HSF configurations. Most models are designed to improve overclocking performance (generally not relevant to building quiet HTPC as it increases heat), and there is considerable variance in noise levels between models. The quieter ones offer obvious noise-lessening benefits over a lot of stock cooling.
If seeking an after-market CPU cooler, consider your case clearance. This is the amount of space from the top of the seated CPU to the lid of the case. Also check the height of your ram, as some coolers sit quite low to the motherboard.
There are a variety of mounting mechanisms, but they all fall into two basic categories – those with, and those without, a backplate. Backplated HSF’s require the removal of an installed motherboard in order to mount the backplate to its underside. Non-backplated HSF’s can generally be attached to the motherboard without removing it from the case. There is a clear advantage to using a non-backplated HS if the machine has already been built, as it may eliminate the need to have to remove the motherboard for its installation.
Look for something with a large, efficient fan.
Passive Cooling
Passive CPU cooling means running the heatsink on the CPU without a fan. This can be achieved by using an appropriate after-market heatsink on the CPU and providing airflow via a source such as a case fan. For example, Antec NSK2480 and Fusion Remote cases have a 120mm case fan right next to the CPU. In this instance, a passive heatsink can be used as there is ample airflow from the 120mm fan. Not all cases are suited to this type of CPU cooling and options will depend on the size and proximity of case fans to the CPU. Be very careful using a heatsinc that is not explicitly suited for passive operation. Passive cooling is unlikely to work with stock heatsinks.
HSF: Recommended:
General Use
Noctua c12p-se14
6 year warranty, min 10dB, 140 x 140 x 25mm
Low Profile
Scythe Shuriken
min 10dB, 105x116x64mm
Passive
Scythe Ninja Mini rev. B
min 0dB, 110 x 110 x 115mm
General Use
Noctua c12p-se14
6 year warranty, min 10dB, 140 x 140 x 25mm
Low Profile
Scythe Shuriken
min 10dB, 105x116x64mm
Passive
Scythe Ninja Mini rev. B
min 0dB, 110 x 110 x 115mm
SETTING UP AND TESTING (once you have your HTPC)
Its important to check your CPU cooling is working correctly after installing a new HSF. If the heatsinc is not installed correctly and too much heat is generated, it can result in fried hardware.
To check CPU temperatures, use monitoring software and max out CPU by running maths that will drive it at maximum heat.
Suggested software:
Monitor temps
-Hwmonitor
or
-Speedfan
Torture test CPU @ max heat
-Prime95
Testing Method
Before you begin, be sure to obtain the correct safe operating temp range for your particular model of CPU from a reliable source (IE, Intel, AMD). Start the PC and check the temps before starting any applications that will cause CPU stress. Safe temperature ranges differ between models of CPU, so Once you can see that the CPU is running safely within this range, start Prime95. Keep a close eye on temps to ensure they don’t go over the safe range. The temperature can climb very quickly, so monitor carefully, especially for the first 5-10 minutes. If they remain in a safe range, continue the test until the temperatures level out and have been running continually for some time (1-2 hours). Make sure you continue to check back regularly as it’s easy to fry hardware that is not properly cooled. Ambient temperatures do affect CPU temps, so if you are testing on a cold day in a room that can get hot, ensure there is a margin allowed for additional heat.
Undervolting
One way of lowering a CPU's temperature is to lower the amount of power supplied to it. In the same way as increasing voltage can contribute to overclocking potential, undervolting can also be an asset in cool running of a cpu. The difference here is that undervolting does not affect CPU performance. Its quite possible to lessen power to the CPU (thereby reducing heat) and retain stock clock speed. This is achieved in one of two ways, either via BIOS settings, or via software.
To undervolt, start with the lowest voltage reduction, start the machine, and run something that will max out the CPU (ie Prime95). Once you have ascertained it is stable, repeat the process with the next lowest setting and so on, until you hit an unstable voltage, then increase to the previous stable increment. Dont be afraid of harming your CPU - this is not risky as long as you have set the CPU up properly to start with and know that your cooling system is working properly. If using BIOS, and for any reason find your machine wont start, just do a jumper reset to factory defaults. (Most modern motherboards will auto-compensate for incorrect voltage settings and this will not be necessary).
PSU
The power supply is an important component choice inasmuch as it will determine how much energy is wasted (via its efficiency), how much heat is contributed inside the case, and also, how much noise it makes.
Overhead
Power supplies are generally most efficient between 50 and 75% load. They also run cooler at lower loading than when they are being pushed to their capacity. For these reasons, there are some benefits to selecting a power supply which is rated above the energy consumption of the machine. This overhead can also be beneficial for providing scope for future upgrades, particularly if adding a dedicated GPU, or using a more powerful one is a prospect.
Consider a PSU rated at approximately 200% of power consumption. This does not mean the machine needs power availability at double its actual power usage. This formula will, however, provide a PSU that will be cool, quiet and efficient, by running at an optimal load. It also provides protection against lost efficiency which will occur over time from capacitor ageing.
Beware also of selecting a PSU which is too powerful, as efficiency can drop off significantly @ < 20% load. While this won't necessarily affect noise, it will affect power consumption. 80plus certification does not measure PSU efficiency under 20%, so the certification (and its indication of efficiency) does not apply if your PSU is too big for your build.
How to calculate PSU size
There are a number of PSU calculators available online. One such example is HERE. If you are considering adding a dedicated GPU in future (or several if you are a Gamer), it would be wise to factor these parts into your initial calculations.
Modular design
Modular PSU's use a cabling system whereby rails are plugged in as needed, as opposed to a non-modular system where all rails are ‘fixed’ to the PSU. The advantages to using a modular PSU is the reduction of cable clutter and slightly improved air-flow within the case.
80Plus certification
80Plus is a program that originated in North America which provides certification to power supply manufacturers that indicate a standard of 80% efficiency or higher. This certification has made considerably impact on the PSU industry, with manufacturers building to attain the certification. Generally speaking 80plus certification is a reasonable base indicator of build quality – higher efficiency means that the components inside the PSU are likely to last longer, and that higher quality parts are used in order for the PSU to run efficiently. 80Plus has four categories:
80Plus – 80-82%
Bronze – 82-85%
Silver – 85-88%
Gold – 87-90%+
Bronze – 82-85%
Silver – 85-88%
Gold – 87-90%+
Passive and Semi-Passive designs
Passive cooling refers to a design which is cooled entirely without the use of a fan. Semi-passive means that the PSU will only use a fan above a certain power draw, (for example, 50%). These models tend to cost more than their air-cooled counterparts, but provide one less source of noise in the overall design of the machine.
GPU’s and power consumption
A dedicated graphics card (GPU) is an important aspect in selecting a power supply. Generally speaking, a mid-range GPU will state a minimum 400-450w power supply as a requirement. Low-end GPU’s may have a stated requirement of 300-350w. This does not mean that they consume that amount of power, but is an indication provided by manufacturers which takes into account most build configurations and their base power consumption, then ensures an additional margin of power is available to ensure the GPU will function well.
Summary:
Look for an 80plus rated PSU with low noise output. Ensure you calculate PSU size carefully against your proposed build and factor in upgrades, particularly the addition of a GPU. Passive and semi-passive designs are preferable as they contribute little or no noise.
PSU: Recommended:
Budget
Corsair CX400
Antec Earthwatts 380w
Mid Range
Enermax EMG500AWT
Passive
Seasonic X400
PicoPSU
150w version available! - low-power machines only
RAM
At the time of writing there are probably more RAM choices simultaneously available than there have ever been for HTPC builders. Starting at 667mhz and going up to 1600mhz or higher, and also in two different flavours – DDR2 and DDR3, and with a large range of timings aimed at stock speeds and also allowing scope for overclocking. Generally speaking, your choice of ram will not make a great deal of difference to media playback quality. In other words, its not necessary to use high-end ram for the purposes of running HTPC software to play and record media. Faster RAM may be useful to builders who are looking at an ‘all in one’ solution, particularly if the machine will be used for gaming or for video editing, or for other RAM-intensive tasks.
2GB vs 4GB
There is some debate currently about how much RAM to use in a dedicated HTPC. Generally speaking, media recording/playback and menu navigation are not ram-intensive tasks. Many builders find that 2GB is more than adequate. If the machine is to be used for heavy multitasking jobs, like running virtual machines, or video editing, extra RAM will be an asset and will be utilised. 32-bit OS’s won’t use much more than 3gb of physical RAM. 64-bit OS’s can utilise far more. Fortunately, RAM is a relatively simple and inexpensive component to add if extra is required. For HTPC tasks at the time of writing this thread, 2-4gb is ample. 6+ GB is unlikely to provide any significant benefit, although this may well change with time, depending on the state of software and OS development.
DDR2 or DDR3
In real world tests there is not an enormous amount of performance difference between the two designs. Motherboard choice will be a determinant of which type to use, as DDR3 ram will not fit DDR2 boards, and vice-versa. There is currently no significant performance deficit for a machine that uses similarly spec'd DDR2 in terms of HTPC tasks. Obviously the benefit to DDR3 is slightly improved general performance and currency/positive resale value.
CASE AND CASE FANS
CASES: GENERAL FEATURES
Cabinet – IMPORTANT!!
The size of the available area in a entertainment unit/cabinet will have implications for the choice of case. Its essential to select a case that will have ample room for air-flow on all sides once its been installed in the cabinet. The rear of the space should ideally be open, to allow exhaust from the power supply and rear case fan/s. The space on each side and above should also be 30-40mm or more to allow for adequate heat dispersal. It is very important that these aspects are taken into account. If confined in a small space, the machine will run hot, or in the worst cases, overheat.
Form-Factor
There are three common form factors used for HTPC builds. In order of size, smallest to largest - Mini ITX, Micro ATX and ATX – with Micro ATX being the most common. Most ATX cases will accommodate the smaller mITX and mATX boards. Most mATX cases will accommodate mITX boards. The advantage to larger boards is more room for expansion. Larger boards require larger cases. If you have limited space for your HTPC, the form factor may be a good place to start. More discussion below in MOTHERBOARD section.
VFD or not VFD?
Many cases offer a front display. These begin at the simple 2-line LED style iMON as seen on cases like the Silverstone LC20B-M and go up to mini-TV style touch-screens as seen on the originAE S21T. I won't discuss pros and cons in any length here, as this is a stylistic choice. Opinions differ as to the usefulness of front displays. Suffice to say that compatibility should be checked in the Forum to ensure the display will function properly with MP.
IR Receiver
Built-in IR offers the ability to point a remote control at the case and have it respond to the commands. Having the receiver built in circumvents the need to run an external IR through a USB cable.
Storage Expansion
An important consideration if you are planning on using your HTPC as a storage device for a large media collection is its capacity to hold additional hard drives. A general rule of thumb is that the form-factor of the case will determine the scope space for additional drives.
Internal And External Drive Bays
In case specifications, the drive bays are referred to as 'internal' and 'external'. External means the bay is accessible from the exterior of the machine. 5.25" bays are usually external. 3'5" bays come in both flavours - external 3.5" bays commonly are used for things like card-readers, and sometimes fan controllers.
Bay Adapters
If short on 3.5" bays for hard drive installation, a 5.25" bay can be used with a caddy which sits on each side of the drive to bridge the space between the sides of the drive and the sides of the bay. SSD's are usually sold with such a caddy so they can be installed in a 3.5" bay. 4x 2.5" to 5.25" adapters are also available (fit 4x 2.5" drives in a 5.25" bay). When considering a case, don’t be put off by the initial specs as it may be possible to fit your preferred drive configuration by using adapters.
Low-Profile Cases: considerations
Low profile cases are popular for HTPC's because of their capacity to fit into small spaces and their clean aesthetic integration into a population of AV gear. There are some implications for the use of low-profile cases that are important to consider:
CPU cooler
The height of after-market CPU coolers is more limited in lowpro cases than full height cases. This can have implications for the amount of noise the cooler makes. The extent of this effect will depend on the TDP of the CPU and the load that it is under, and on the ambient temperature inside the case and its effect on the CPU temperature.
Expansion / video cards
Low-profile cases require low-profile cards. With many expansion cards this is not an issue, but it does pose implications for the choices of video card available, as not all models are available in low-profile. If you have a particular kind of video card in mind when building your machine, it would be worth checking to make sure it will fit. The same maxim applies to tuner and other expansion cards - check that the model you want to use is available in lowpro first
For more information on video cards see the VIDEO CARD section, below.
The case's capacity to provide good airflow to all components is an essential aspect of quiet operation.
Rule of thumb - large, low-RPM fans are generally quieter than small, high-RPM fans.
Rule of thumb – fewer fans = less noise
If comparing HTPC cases for their potential to run quietly, consider the size and placement of the fans – check where the airflow is sourced from and where it exits the case. Ideally, there will be streams of air that will reference hard drives, motherboard chipset, graphics card and CPU.Rule of thumb – fewer fans = less noise
Fan speed
Fan speed is affected by the amount of power sent to the fan. This can be affected in a number of ways:
1. Fan choice and fixed RPM
Fans are available at various ratings, from 500rpm to 2000rpm. If not using a fan speed controller, the base RPM design will provide some indication of how loud the fan will be at fixed voltage, and of how much air its capable of moving.
2. Analogue speed controller
Analogue speed controllers are a popular choice and feature one or more analogue dials, each of which controls available voltage to a fan. By turning the dial, fan speed can be increased or decreased. The upside of this type of control is the extent of fine control over fan speed they provide. The downside is that they take up a 5.25” or a 3.25” drive bay and create some cable clutter inside the case.
3. In-line resistor
A resistor lowers voltage availability to the fan by sitting in-line between the fan and its power source. Many quality after-market fans are supplied with either one or two resistors, which allows for modular control of fan speed. Resistors of this type have a female and male plug and simply attach in-line.
4. Chipset/motherboard control
Achieved by attaching a fan with a speed controller wire additional to its + and – wires to a compatible fan header on the motherboard.
5. Sotware control
Can be achieved with software like Speedfan. The degree of success achieved will depend on the chipset compatibility of the motherboard with the software, and on the Users ability to correctly utilise the features of the software.
CFM, dBA And Choosing A Fan
‘Cubic Feet Per Minute’ (CFM) refers to how much air a fan can push at a given speed over time. dBA refers to decibel pressure, or audibility to the human ear. There’s generally a positive relationship between CFM and dBA (more air being shifted = more noise).
When picking a case fan, look for something that has the best air flow for the lowest noise level. Some case fan manufacturers cite life expectancy in terms of hours of use (i.e. max 130,000hrs). This figure can also act as a good general indication of the build quality of the fan.
PSU Can Be Implemented As A Case Fan
PSU’s with a 120mm top fan can be used to extract hot air from the case. Some cases allow for upside-down mounting, with the 120mm fan extracting from inside the case, rather from outside it. Given that the PSU fan will be running anyway, its can be efficient to experiment with utilising it for heat exhaust. The downside is that if you have some very hot components running in the case (i.e. high performance hard drives, or a high-end video card) you will be introducing hot air into the PSU, which could have implications for its efficiency and life-expectancy. Obviously the decision to do this or not will depend on your component choices and on existing heat of PSU and on the load it is working under.
STORAGE
SSD or not SSD?
SSD’s seem to be the current flavour of the month for many PC builds. Fast SATA SSD’s offer read/write speeds of up to 270 MB/s, which is more than double the speed of most fast HDD’s. Fast PCI-E SSD’s offer speeds up to 700-800mb/s (eek!).
PROS:
Extremely fast data transfer speeds compared to most spinning disks.
PC’s boot a lot faster
Programs installed on the SSD load more quickly
Generate very little heat
Low energy consumption
Silent
CONS:
Very expensive
Limited storage
Performance degrades over time. See TRIM
SSD’s offer some nice benefits to HTPC users, but add a premium to the price of a new build. If you can afford it, there is no reason to ‘not’ have one (ie no significant negatives). However the actual benefits will depend on how you use your HTPC. HTPC’s generally aren’t booted very often – with most users preferring to use sleep mode (s3/s4) when the machine is not in use. So, the decision to buy one might relate to a question like “how quickly do you actually need your favourite media centre application to load”?
SSD: Recommended:
OCZ Vertex LE
(SSD technology is moving fast ATM, so be warned - this recommendation will date very quickly!)
OCZ Vertex LE
(SSD technology is moving fast ATM, so be warned - this recommendation will date very quickly!)
Hard Drives
Fast (10,000rpm) hard drives generate quite a bit of heat, and can be noisy. More drives installed together in the same case equates to more heat generation. Compared with performance and standard 7200rpm drives, ‘Green’ HDD’s consume little power, run cooler, and make very little noise. They are a good choice for HTPC builders. Green drives which typically run at 5400rpm are more than capable of recording multiple television programs simultaneously.
This is not to say that fast HDD’s cant be used in an HTPC - and builders with gaming in mind would be wise to consider their options here, particularly in the 7200 RPM range, but that there are compromises to be considered with faster, high-performance models.
For more information on Drive surface temperature and sound levels, see HERE
2.5” hard drives are quieter than their 3.5” counterparts – so a good budget option if seeking to build a silent client machine without the expense of an SSD may be to go this route. There is a slight size
rice premium for 2.5” drives over their 3.5” counterparts, but not to the same extent as current SSD prices.Some HTPC users opt to have a two HDD configuration, where one HDD is used as a dedicated operating system / program drive [typically small in size, <320GB], and the other drive is for media storage[>1TB]. The main benefit of this setup is that it is very easy to upgrade the storage capacity without having to go through cloning a HDD or reinstalling the operating software.
Storage: Local or network?
There are two basic storage configurations to consider for an HTPC. The first is to store media in the case of the HTPC itself. The second option is to use a server and client, with the media stored in a server machine and accessed through client HTPC(s) via LAN or wireless network. The decision as to which configuration is preferable will depend on the size of the HTPC case, how many hard disks it can hold, and how much media needs to be stored.
MOTHERBOARD, On-Board and On-CPU Graphics
On-Board Graphics
In recent years the need to use a dedicated video card has lessened with the release of a number of motherboard chipsets that are capable of HD playback. Perhaps the main differentiating point between these chipsets for HTPC users, is the difference in their ability to pass multi channel audio through HDMI
Examples:
There is more information in the Forum regarding on-board graphics/CPU configurations. The basic advantage is lesser power consumption, lower cost, and a free pci-e slot. The disadvantage is that on-board graphics are less powerful and can be limited in reproduction of some HD content (specifically 1080i if paired with an inadequate CPU). At the time of writing, no on-board graphics support audio bitstreaming.
On-CPU graphics
The current generation of Intel Clarkdale CPU’s have a GPU built in. This is a relatively new development in CPU/Motherboard technology, and is possibly the way that CPU technology will head in the near future. The built-in GPU on the Clarkdales has produced some solid benchmark results compared to the range of available on-board chipsets. They also support audio bitstreaming, which is a significant comparitive benefit at this time for Audiophiles. At the time of writing this thread, initial reception was positive, although there have been some mixed reports about their ability to accurately output at 24p.
GRAPHICS CARDS
Passively cooled GPUs are popular in HTPCs because they contribute zero noise. The current state of play is that Radeon 5 series is the only market contender that offers audio bitstreaming. For this reason they are very popular among HTPC builders.
For those using their PC to watch and record TV, there are benefits to using a card that can manage vector adaptive de-interlacing with edge enhancement. For more information on VAD, see THIS thread.
GPU: Recommended:
ATI Radeon HD 5570
DX11, Eyefinity, Audio Bitstreaming, high quality de-interlacing, 7.1 audio through HDMI
Passive:
ATI RADEON HD 4550
DX10, high quality de-interlacing, 7.1 audio through HDMI, 0dB
ATI Radeon HD 5570
DX11, Eyefinity, Audio Bitstreaming, high quality de-interlacing, 7.1 audio through HDMI
Passive:
ATI RADEON HD 4550
DX10, high quality de-interlacing, 7.1 audio through HDMI, 0dB
If not requiring de-interlacing of 1080i material, a relatively modest GPU is perfectly adequate for HD playback. My recommendation would be a (2xx series or a 9xxx series nVidia), or a (4/5 series Radeon). Any of these cards will offer hardware accelerated HD playback.
Please see the section PSU, above, for information on power utilisation of dedicated graphics cards, and their relationship to PSU choice.
MORE INFORMATION
HTPC builds:
Excellent, up-to-the-minute HTPC build suggestions at Whirlpool Forums
Renethx’s collossal, encyclopaedic HTPC build guide
Hardware – General:
Compare GPU specifications side-by-side at GPU Review
CPU benches at TomsHardware
GPU benches at TomsHardware
SilentPC reviews – HDD, PSU, Fans
Cases:
Antec
Silverstone
OriginAE
Lian Li
Thermaltake
Zalman
A-Tech (Heatsink/Passive cases)
HFX (Heatsink/Passive cases)
Fans/cooling:
Noctua
Scythe
Zalman
Top 5 Silent Heatsinks - Frostytech
PSU:
Seasonic
Corsair
Silverstone
Forums
XP MediaCentre
AVSForum HTPC section
AVSForums HTPC Section
Whirlpool Desktops – excellent build discussion community
Truely silent PC
Idiocratease's HFX build
Tweaktown - The sound of a silent PC
Excellent, up-to-the-minute HTPC build suggestions at Whirlpool Forums
Renethx’s collossal, encyclopaedic HTPC build guide
Hardware – General:
Compare GPU specifications side-by-side at GPU Review
CPU benches at TomsHardware
GPU benches at TomsHardware
SilentPC reviews – HDD, PSU, Fans
Cases:
Antec
Silverstone
OriginAE
Lian Li
Thermaltake
Zalman
A-Tech (Heatsink/Passive cases)
HFX (Heatsink/Passive cases)
Fans/cooling:
Noctua
Scythe
Zalman
Top 5 Silent Heatsinks - Frostytech
PSU:
Seasonic
Corsair
Silverstone
Forums
XP MediaCentre
AVSForum HTPC section
AVSForums HTPC Section
Whirlpool Desktops – excellent build discussion community
Truely silent PC
Idiocratease's HFX build
Tweaktown - The sound of a silent PC
Many thanks to Shaun (DobbyDB) of Whirlpool Forums for his generous editorial assistance in writing this guide.
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