[mythtv-users] High-Definition Playback performance data

[Pete]

Jarod Wilson wrote:

>I've lost track of the thread where I said something about trying a GeForce 
>6200 in place of a GeForce 4 MX with an Athlon XP 1800 system, to see if that 
>would give any significant playback performance boost with High Definition 
>recordings. Well, the answer is no, not really, but a bit of a cpu upgrade 
>sure helped. Here's a quick summary of my findings today (from memory though, 
>wish I'd actually written it all down). In all cases, I'm using libmpeg2 for 
>decode.
>
>Athlon XP 1800 w/AGP GF4MX, 6629 nvidia driver:
>
>-Able to play back 720p, cpu around 85% used.
>-Able to play back 1080i without a deint filter, cpu around 95% used.
>-Stutter every second or two on 1080i with deint filter on, cpu completely 
>pegged.
>
>Athlon XP 1800 w/AGP GF4MX, 7174 nvidia driver:
>-Able to play back 720p, cpu around 70% used.
>-Able to play back 1080i without deint, cpu around 85% used.
>-Stutter every few seconds on 1080i w/deint filter on, cpu pegged.
>
>Athlon XP 1800 w/AGP GeForce 6200, 7174 nvidia driver:
>-Maybe slightly better, but no significant difference from the GF4MX.
>
>Athlon XP 2600 w/AGP GF4MX, 7174 nvidia driver:
>-Able to play back 720p, can't remember cpu usage.
>-Able to play back 1080i w/no deint, can't remember cpu usage.
>-Able to play back 1080i w/kernel deint filter enabled, cpu usage fluctuates 
>between 80 and 95%.
>
>I've decided to stick with the 2600 and GF4MX, and my secondary Myth box can 
>now handle 1080i programming without a problem. I'll get the missing cpu 
>utilization numbers one of these days...
>
>  
>
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>
I'd like to know what I can do get that kind of performance. I've got an 
Athlon XP 3000 (512 MB RAM) and an FX 5200 (AGP) running myth .17 and 
FC3 (everything is from atrpms) where HD is close, but not quite. After 
a lot of hacking to get the channels to work, it finally comes up, but 
I'm getting lousy performance, with a lot of audio buffer underrun's 
(using spdif through an on board nvidia audio chip) and video stutter's. 
I'm using a pcHDTV 3000 with the 2.0 driver running in dvb mode. I 
turned off deint, and turned on libmpeg, but I think the only diff was 
the deint setting. I'm about to restart X with the NvAGP setting set to 
1 to see if that helps, but I'm guessing no. XvMC doesn't work at all 
with the driver from the nvidia site. Would it help to download the 
driver from atrpms (currently using 7167)? I assumed they were probably 
about the same. Also, does myth use xv by default or did I miss a 
setting somewhere? Standard def playback is about 30-40% of the cpu, 
which I think is pretty high too, but am less sure about that. I know 
I'm missing something, but I can't find it in the archives (and I've 
gone back to about September). Anyone know what I'm doing wrong? Note 
that right now, this is a dual front and backend box, but it's not doing 
anything else at this point, so it shouldn't be an issue.