CPU as it relates to video performance

[johnnysnap]

I'm pretty sure I know the answer to this but here goes....
I have a RADEON 9000 pro with the current config:
svid/composite from DTV receiver to 9000.
9000 to TV via svid/composite.
Running ATI multimedia center to record and view tv etc...
Drawbacks are lack of guide integration and recording integration.
Actually, thats why I'm here in this forum... I'm looking for better integration.

The short list was XP Media center or Sage. I ordered sage today, made a run to compusa for a 250 card and had the whole setup running in a few minutes.

Heres the problem:
I'm running this on an PIII 500 with 512M RAM.
When I run the video input into the 250 and out the 9000 to the TV the video is awful. I mean really pixel like and distorted.
By contrast if I go into and out of the 9000 the video is great. Almost as good as a direct feed into the TV from the sat receiver.

Can this ALL be explained away by CPU speed? If I upgrade this machine to a 2G P4 or so will it be as good as a pure hardware solution like the RADEON?

Can I possibly use Sage with the RADEON alone and not include the 250? I haven't seen a way to do this yet.

Thanks for the help...

[dkardatzke]

Are you playing back recorded video with your 9000 as a comparison or are you just using the pass through feature of the 9000 to watch straight video with no encoding or decoding? If the 9000 is capable of playing back any MPEG-2 recorded file with no pixelation, then it's just a quality setting issue/filter option from within SageTV.

Also, SageTV does not currently support using any ATI cards for TV tuner purposes.

[mlbdude]

Sounds like you are comparing the MPEG2 compressed video that comes out of the 250 to the non compressed passthrough version. It also sounds like your compression settings are set pretty low. Make sure they are set to 2 GB or 3 GB per hour for best results. Also, make sure to enable hardware assist decoding in your Hauppauge INtervideo drivers. It will help with that low CPU.

[johnnysnap]

Well, there are a couple of issues here. First, the 9000 does record fine (dropping a frame or two at the beginning) and the playback is pretty good so maybe it's just a settings thing. HOWEVER, the biggest problem is not the recording but the simple playing of video.
When I run the input through the 250 and out the 9000 (using the pci bus to transport) the video quality is very bad. It seems real grainy and spots of pure black get all pixelated and stuff. The audio is a little out of sync, just enough to be annoying.
I recorded some stuff and played it back and it's un-viewable, choppy with dropped frames.
I understand your point about settings as the encoder card shouldn't have to "pass" the data to the video card in order to be recorded but I still can't understand how the 9000 is able to record better than the 250 when I don't think the 9000 even has a hardware encoder....
I recorded a 3 hour baseball game with ATI recorder and it was 9 gig. So it is recording pretty high quality as well. (my unsuccessful 250 encode was set to 1.5 Gig/hour, and still sucked in playback)
I'm a little perplexed at the moment. What kind of settings should I look at?
I'm trying to find a way to get a box with a little more horsepower to try but until then I'd like to learn as much as I can about tweaking this thing for performance.

[mlbdude]

Have you compared your 3 GB (MPEG2?) ATI recording to a Hauppauge 3 GB per hour recording? What are you using to play back any of these files? Are the defects you are seeing in the MPEG2 stream or rendering problems (I.E. you play it back on another computer and it does the same things in the same places)?

Recording should be possible with the 500 Mhz. MPEG2 playback should be as well as long as you have the CPU dedicated to it.

[johnnysnap]

Thanks for the reply.
Actually the ATI recording was 3GB/hour and the Hauppauge was at 1.5GB/hour. I played both of them with the ATI player as the recording didn't show up in the Library in SageTV.
The ATI recording was much much better. I agree with you, there is something not right. I'm confident I can fix that with settings or whatever but I'm still not sure about the basic underlying question in this thread:
Is the process of simply playing Live TV within SageTV processor intensive?
If I upgrade the CPU will I see an increase in the quality of the simple task of displaying TV?
Does the 250 card have to encode everything that passes it's lips? or can it simply pass the stream to the video out?
I can NOT be convinced that the PCI bus if flooded by a simple video stream....
Somewhere there is a magic setting... I hope.

[ku71]

It's unlikely the low quality is related to CPU performance.

To find out about your CPU load, I recommend installing Motherboard Monitor. Use the dashboard to make sure it's working and reading the correct sensors. Then activate the OSD and add the following OSD script (under OSD, osd script)

<text><Temp 2 Value>/<Temp 1 Value>
<br>
<text><CPU Load 0 Value>/<CPU Load 0 Average>
<br>
<text><CPU Load 0 Lowest>/<CPU Load 0 Highest>

this shows the CPU load on screen. (the temp sensors may not be correct, it depends on the mainboard)

To solve your problem, make sure you compare the video quality at the same compression settings.

[mlbdude]

Yes, make a comparison with the video using the same compression rate. Either increase Sage to 3 GB or reduce the ATI recording rate. Processer is not an issue here. Watching TV in Sage is processor intensive. It is decoding the MPEG2 stream. You will probably be around 70-80% with a 500 and no hardware assistance. With hardware assistance you should be able to hit 50% easily.