[mythtv-users] Re: minimalist hardware for mythtv backend using PVR-350 or PVR-250?

Yan-Fa Li yanfali at best.com
Tue Oct 12 22:04:23 UTC 2004


Nice.  An AMD/NatSemi Geode.  Personally I would stay away.  The 
performance just running the linux kernel is abysmal.  I have an old 
Virgin Web Terminal with a similar CPU and it was slow as molasses.  The 
biggest issue with older slower CPUs is memory bandwidth, they simply 
can't do as much because they can't get data in and out of the CPU fast 
enough.

If you get it to work, more power too you.  It's also not an 686 class 
CPU.  Last time I checked the optimal CPU configuration for it under 
Linux kernel was a 586/pentium.  This thing probably only supports MMX 
at best, or possibly 3DNOW which means transcoding will be a nightmare.
One nice thing about having CPU to burn for the backend is you can use 
it to transcode in the background, or commercial skip.

Also, remember if it only supports UDMA33 the PCI bus will be tied for 
up 3 times as long as UDMA100 which might cause some unpredictable 
behavior with your other PCI cards.  When you get it up and running, try

	hdparm -tT /dev/hda

and post the numbers.  I'd be willing to bet they are very low.  For 
mpeg2 you only need to support 1MB/s max writes.  So your PCI bus 
shouldn't have to transfer more than 2-4MB/s.  PCI32/33 can support 
45-90MB/s comfortably.  Of course if you want VGA and Audio support on 
top of that, you might be asking a little much of the little fella.  Let 
us know how it works out.

Andrew Plumb wrote:

> Hi Tom,
> 
> I picked mine up from EMJ Embeeded, now called WDL Systems:
> 
> http://www.wdlsystems.com/modperl/view_services.cgi?request=list_aisle&aisle_id=196&asibs=eldest_first#accessories_xboard
> 
> They aren't the cheapest thing out there, but they are tiny and I'm
> sure if you're going to manufacture something which uses thousands,
> you'll get a bigger price discount. :-)
> 
> Andrew.
> 



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