[simon-042]

Morning!

I've been a reader of the XBMC forums for a while but I'm starting to have a couple of performance issues and was wondering if any of you could shed some light on whether an upgrade or a rebuild would be needed to get what I want from my aging HTPC.

Having looked at the stickies it's pretty clear that I am moving from group 1/2 into group 3 and I'm having problems with the more bitrate intensive 720p files I want to play (50fps, 4000kbps, 5.1 audio), and 1080p is currently a dream... I'm not interested in multi-tasking as I have a NAS machine for the download and storage of media and a laptop in the lounge for the web.

My current HTPC is pretty basic and made up from old PC parts I had lying around:

Intel Pentium 4 3Ghz
Asrock P4VM890 (This has SATA and one PCI-E x16 connection)
1 GB RAM
250GB HDD
Nvidia 8300GS
Windows XP
Antec Fusion Case

I know I'm not getting the best from the GPU under XP and I've tried installing XBMC Live to enable VDPAU, but the performance gains are negligible (the stuttering is less intense and a little less frequent but definitely unwatchable).

I know it must be possible to play HD content on an older CPU but is it worth upgrading the GPU to the Nvidia 210 or 240 series and pursue the use of VDPAU under Live with the current system or consider a very budget rebuild using the recommendations in the forum stickies?

Thanks for your help guys!

(BTW I'm at work so I may not be able to respond to questions straight away.)

[teeedubb]

It looks like that video card supports vdpau. Are you sure vdpau is being used when you play back content in xbmc-live? Alsohow much ram is xbmc using?

[simon-042]

I noticed a small improvement on Live vs Windows but that might just be Live using less resources. Other than checking the box and playing the file is there any other way to check VDPAU is on?

I can check the RAM usage under Windows tonight, is there a way to do that in Live too?

[teeedubb]

I think the easiest way to check would be to load xbmc, play an offending file and press o on the keyboard when on the playback screen. This brings up stats for the file being played, if vdpau is being used you will see something along the lines of dc:ff-x264-vdpau. You could also check the log file or use another program such as vlc or mplayer to test.

Sorry I meant how much ram allocated to the video card, from memory 512mb is recommended for vdpau.

Also, could it be the type of media thats being played? Maybe the codec isnt supported by the vdpau feature set of your video card..

[simon-042]

Thanks for the clarification Teedub!

I checked the RAM and CPU load in Windows during playback neither was maxing out, some spikes occurred but these were due to background processes and disappeared when the processes were killed, so in Windows at least the video card is definitely the problem.

I'll have another tinker in Live to check RAM allocation and VDPAU activity during playback later today.

I had a quick look at this:

http://en.wikipedia.org/wiki/Nvidia_Pure...HD.29_GPUs

Looks like the 8300GS is VDPAU set B which has some resolution restrictions, pretty sure I'm running a custom resolution to fit on my HDTV at the moment so that's another thing to check! Although it looks codec compatible as the file I'm playing is h.264 and that is listed for VDPAU set B.

Assuming all this doesn't help me find the problem, would purchasing a Nvidia GT520 help out at all? This pushes the VDPAU feature set to the latest possible but would it end up being constrained by the P4 processor in any way?

Thanks for your help!

[eskro]

i'd try openELEC if i were u

[simon-042]

Ok, so here we go...

The custom resolution on my HDTV is not outside the accepted capability of the card. So the problem isn't there.

Tried the file on Live again, pressed "O" for the details and the VDPAU is definitely not engaging for playback. Stats show I'm only hitting 30-40fps on a 50fps file.

Installed OpenElec and tried playing the file through that, the file wouldn't even play!

I can't allocate more than 64MB to video in the BIOS (it's pretty ancient!) so getting near 512MB isn't going to happen.

On the basis of all that it's probably best to go back to the original question of the thread, would a graphics card upgrade help at all or is a rebuild inevitable?

[eskro]

well, magic number for video cards is 512mb ram

64mb is a no go for 1080P

[teeedubb]

If a 1.6ghz atom can handle 1080p with vdpau I don't see why your setup wouldn't. I'm not current on video cards, but from memory the gt220 + gt 430 are great cards for htpcs. I remember reading that the gt210 + gt520 are weak when it comes to vdpau...