[mythtv-users] HDTV CPU - will this work?

[Brian Wood]

On Feb 3, 2007, at 7:50 AM, Rod Smith wrote:

> On Saturday 03 February 2007 03:09, Mitchell Gore wrote:
>> Hi,Just wondering if you think a AMD Mobil Sempron 3000+ would  
>> handle HDTV
>> decoding with out XvMC?Thanks,Mitchell
>
> My system is similar, but not DIRECTLY, comparable to yours. I've  
> got an Intel
> Celeron D 3.06GHz, which should theoretically be pretty similar in  
> speed to
> yours. I don't have an HD TV set, but I do have a pcHDTV card, so I  
> can
> record HD content (in theory -- in practice my signals are weak  
> enough that
> it's hard to get a stable recording). I can play back reasonably  
> well when I
> use an nVidia MX4000-based card and the binary nvidia drivers, with  
> about 55%
> CPU time used by mythfrontend with XvMC or 70% CPU time used by  
> mythfrontend
> without XvMC. X itself takes another 10% CPU load in both cases, so  
> I'm
> pretty sure that's pretty close to the limit for the system. When I  
> swap in a
> video card based on a SiS 330 (aka Xabre 200), though, the  
> mythfrontend CPU
> use stays at 70% but the X CPU use jumps to 30% and I get brief  
> pauses in
> playback about once a second.
>

What you say is why I suspect the Sempron won't work well.

Recording HD takes almost no CPU, so that means nothing.

The Sempron is theoretically more or less equal to the Celeron 3.06  
but in practice you'll find the Celeron a bit better for several  
reasons.

If your CPU load numbers came from top they are averages and your  
actual peak use is higher.

It is barely possible for the Mobile Sempron mentioned to work if  
everything else is totally optimized (minimalist Xserver, good video  
drivers, nothing not needed running etc.) but it would be on the  
ragged edge if it did.

The OP didn't mention what video hardware he's planning to use but  
since he said "without XvMC" I suspect it is not nVidia H/W and thus  
there would be even less likelihood it would work well, as you say  
you have trouble with non nVidia H/W.

I personally wouldn't plan on it working, but it might be interesting  
to try :-)