HD makes my HTPC struggle. New CPU or new system? (1 Viewer)

[Teaboy]

I currently have MediaPortal running on a Mobile P4 2.8, but my motherboard (8IPE1000-G) doesn't support speedstep so the CPU is locked at 12x. It has 1GB of PC2700 memory in dual ddr mode. It's running in 768x576, plugged into my TV via S-Video.

It's running fine at the moment and everything is perfect, however I've just ordered a new HDTV (KDF-E50A12) so I tried playing a few HD clips on my HTPC. On the XviD/DivX clips which are 720p, the clips look excellent and run flawlessly. On the .ts files which are 1080i the video is very jerky and generally unwatchable. The HTPC also becomes unreponsive while the video is playing.

Now my question; As most sites that allow you to download the clips recommend a 3.0GHz CPU, shall I buy myself an expensive P4 to fit in this board (like a 3.4EE or something - I just found one on eBay for £400) or shall I spend a little bit more and get a new board, CPU and memory?

Or perhaps there's a way to get the HD content to run on my current hardware?

 

[htpcoz]

The HD playback thing has been a thorn in my side for some time now...

I've had success on and off for some time, back before I used MP i used a few other apps developed specifically for my Twinhan card. The other software was able to get HD playback going without too much of an issue, but for some time now stable HD playback has eluded me with MP.

I have a similar spec to you I'm running with a 2.8 P4 though with 800 FSB matched to PC3200 ram. I believe the greatest impact on HD playback I've found to be is the video card, which is currently a Radeon x700 with DDR2 ram (not the PRO). I display this via an RGB->Component adaptor with power strip in 1920x1080x25hz(interlaced)

I am typically using the NVIDIA PureVideo codec, although I've tried with some of the other codecs without much luck either. I find overall the NVIDIA gives the best general playback quality, so I've stuck with it.

What I've found is that when performing HDTV playback on my system the playback isn't smooth at all. It appears like it is skipping lots of frames. In this situation if I look at the MP playback statistics it doesn't show any dropped frames. The CPU isn't maxed out (probably around 60-70%). I would have expected it to drop frames if the CPU was maxed out but it wasn't.

So looking a little further I found that if I change the deinterlace mode from "Best" to Bob, it made no huge difference to my CPU utilisation but all of a sudden my HDTV playback was perfectly smooth (except strangely for 7HD which is 576P. I think the progressive signal confuses the NVIDIA codec). The overall picture quality I think appears to suffer a bit with this change, but it allows me to run HDTV.

So I would say that in my case the video card (a 'relatively' high spec one) is just not capable of performing the intelligent deinterlacing on the high bandwidth HDTV stream. I've tried playing with the different NVIDIA deinterlace modes (pixel adaptive etc..) without any success.

I thought that perhaps it is a limitation of the NVIDIA codec on the ATI hardware, but I've tried Cyberlink as well as Intervideo codes with the same results.

Overall I don't watch much HD content, so I've stuck with the best SD configuration I can get which is Nvidia codec, smart deinterlace. Which gives me great quality for SD, and I'm not worrying about HD for the moment.

I've seen some people discussing issues with video bandwidth issues for HD on 128bit memory bus cards. I've also thought about moving to a NVidia purevideo card, but to get the full purevideo support I would have to upgrade to a pretty expensive (and noisy) card. For the moment the X700 works well for SD, and is fanless. So I think the status quo might be the best for me.

I don't see a lot of discussion about these issues on the forum, so the other possibility is i'm full of sh!t, and I've just got hardware/configuration problems, or there aren't that many people displaying HD material.

I'd be interested to see how you get along though.

 

[Callifo]

Ive got a few demo HD (1080i) files that Ive tried on my MP box which is only a 2600+ (1.8GHz, rest of specs is below) and they worked fine. The HD mpeg2 files work fine (50% cpu usage odd) but quicktime is atrocious, even my 2.8Ghz P4 games box wont play those suckers back.