Multi processor support (1 Viewer)

[SpudR]

Not sure where to post this one, but I guess here will do (feel free to move it if you wish )
How does MP perform on a multi-processor platform?
Is it worth me forcing MP to have an affinity of 2?
Would there be any performance gains on a dedicated system??

I HAVE already forced this - and set the performance to 'high' but MP doesn't seem any quicker...
Just posting for curiosity (if it's truely multi processor compatible I'll reset it...!)

Thanks for your help on this and THANKS LOTS for the release of 1.0.2

 

[DaiC1]

I,ve been playing around with various affinity setting myself, which ever way I set them dosnt' seem t make much differance. My systems running great at the mmoment {Win 7, MP 1.02 n a dual core amd pltform} so I've left the affinity to defauls.

 

[tourettes]

Just leave the affinity to the default (all CPUs). MP itself does almost all of it's work in one main thread (rendering etc.). There are few things that actually benefit from dual (more) core CPUs.

- Video decoding (audio can be decoded on other CPU, this is handled by directshow automatically as it has multiple threads)
- Some video codecs are able to use multiple cores (ffdshow multicore build(?) and CoreAVC.)

 

[SpudR]

Ok thanks guys - I didn't notice much difference anyhow.
I was interesting to set the affinity to the second processor ONLY and run in 'realtime' - this made the gui super slick, but no noticable difference in audio or video performance...

 

[tourettes]

Ok thanks guys - I didn't notice much difference anyhow.
I was interesting to set the affinity to the second processor ONLY and run in 'realtime' - this made the gui super slick, but no noticable difference in audio or video performance...

If changing process priority to real time makes something smoother there are two possible causes for that

1) You have some CPU hogging process running on background that will cause high CPU spikes
2) Just a placebo effect as process priotiry itself won't affect the smootness of GUI / video rendering

About the audio / video performance, decoding audio takes only few percent of CPU power, so there shouldn't be any visible difference in performance (i.e. less dropped frames). Especially if you haven't had any dropped frames earlier then there even cannot be any difference

 

[SpudR]

Further testing reveals it is indeed just a 'feel good' factor - no REAL speed gain at all...

 

[tourettes]

Further testing reveals it is indeed just a 'feel good' factor - no REAL speed gain at all...

That is pretty common when someone fidles with different settings. It feels good if someone manages to find some setting that "improves" something

 

[pharaohamps]

I can't say anything about 1.02 as I'm not using it, but I did have some issues with processor affinity recently.

I built an HTPC for a second TV in the house, and I'm streaming all content to it over a wireless network. Interestingly enough, playing back 720p MKV's over the wireless is smooth and problem-free, but playing 640x480 XVID AVI's would cause the video to stutter and freeze every few seconds. The audio was still fine, and the AV sync would fix itself after a few frames. This is using FFDShow for XVID and CoreAVC 1.9.5 for H.264

The machine stats:
Intel Atom 330 @ 1.6GHz, dual core with HT (looks like 4 cores in Task Manager)
2GB RAM
120GB HDD
Edimax PCI wifi card
XP SP3

This should be able to play videos over a network without a lot of problems, right? Wrong.

I tried various settings and nothing fixed it. I opened up Task Manager while MP was windowed to look at my network utilization, and it was well under 10% with a link speed of 54MBps. Even mounting a DVD and playing the ISO over the network didn't get me to more than 15% utilization. DVD playback was also laggy.

I looked in the Performance tab, and for some reason my "Core 3" (4th core) had a much higher load than the other 3. None of my processes run on any particular core except for SpeedFan, which runs on Core 3, but SpeedFan is very light in CPU utilization. Setting MP's affinity to 0 1 2 fixed my stuttering. I don't know if it's a problem with FFDShow or MP or my processor or anything else, but preventing MP from running on Core 3 made all 4 cores run at about the same % load.

Does MP 1.02 have built-in settings for processor affinity? I had to use a 3rd party program to make sure mine gets set up at boot time.