[mythtv-users] What's up with Matrox Myth performance?

[JC]

My Matrox G200-TV is running 0.8 perfectly on my Dell 4100, P3-800 w/512mb
ram, 80gb 7200 rpm, Mandrake 9 / 2.4.19, SB 64 (ens1371) system.

However!  The only "decent" mode I can run with is HWJPEG Decimation 2/2,
MP3 Q9 32k.  Anything else is unusable (super jerky, etc.).

Yet, I read in page one of the docs that:

   "A PIII/800Mhz system with 512MB RAM can encode one video stream using
the RTJPEG codec with 480x480 capture resolution and play it back
simultaneously, thereby allowing live TV watching."

I can't even do 350x480.  Is it because of the Matrox?

Is it because I'm only using the ONE card with framebuffer support and it's
sending its output to my monitor and video out simultaneously through KDE
(tried a lighter window mgr and no major diff)?  Am I missing some big
XConfig option or optimization?  I have dma turned on and get 20MB/s at a
minimum.

I'm about to go out and buy a fast Athlon and new mobo to fix this but
before I do, I want to be sure that I'm not going to be handicapped by the
card.  I think I read that it won't do 640x480 no matter how fast my cpu?
Really?

Anybody with a G200 or G400 for their capture and video out got it working
better than this?  If so, please tell me what to do / buy!  I'm stuck in
350x240 land at 3GB/hr... yuck!

Thanks in advance,
JC