MythTV: Via Epia Me6000 versus Haupauge pvr-350 tv-out

[konkas]

I have a gentooinstallation on an Via Eia ME6000 mini-itx motherboard
with an svideo onboard.
I also have a Haupauge pvr-350 card installed on this system.

Is it better to use the svideo out on the motherboard than using
the tv-out on the 350 card?

If I run X in the 350's framebuffer its very slow when running mplayer.

If I run X on the motherboards builtin graphicschip and svideo-out
mplayer is faster.

Which on is to prefere when using MythTV?