[mythtv-users] How much horespower for frontend?

[Brian Wood]

On Sep 25, 2006, at 5:59 PM, James Pifer wrote:

> I've always used a MediaMVP for watching recordings on my TVs and
> therefore missed out on the advantage of the frontend. I finally  
> picked
> up an FX5200. It's a PCI model since my machines do not have AGP or
> PCIe.
>
> Anyway, I first installed it in my backend machine which is:
> AMD Athlon 1400+ (I believe this is around 1Ghz)
> 768 MB Ram
> 400+ GB Hard Disk
> PVR350 & PVR250
> FC5 & myth 0.20
>
> I immediately noticed some issues, with both the SVideo out and with
> connecting the VGA directly to my projector. Besides a brightness  
> issue,
> playback does not play well. I get a lot of stuttering, although no
> errors on the frontend while playing it in a terminal window.
>
> For example, if I put CNN on where stuff constantly scrolls across the
> screen, it constantly stutters. It's not smooth at all. I tried  
> watching
> a football game over the weekend and it was unwatchable.
>
> So I pulled the FX5200 and stuck it in another machine. Exact same  
> specs
> on the machine, except 512 MB RAM, minus the PVR cards, minus
> mythbackend and lirc, etc. I got the same results. Swap does not  
> appear
> to be being used at all if I look at 'top'.
>
> I'm NOT doing any HD. Are these machines not powerful enough for  
> this? I
> have not seen the CPU go above 40%. I'm getting extremely frustrated
> now. I would really appreciate it if someone could give me some  
> input. I
> had one person try and give me a hand with the brightness issue in a
> previous post, but this performance issue makes the brightness issue
> take a backseat.
>
> Any help or suggestions is appreciated.
>

Are you trying to de-interlace?, some of those routines might tax  
that little CPU, remember that the number shown by top is an average  
and you might be peaking well over that, though 40% seems like it  
should be OK.

I also wonder about the PCI video card, that's a real potential  
bottleneck.

Are you using XvMC? You might need it but I'm not sure how well it  
might work with a PCI video card.