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

Andrew Plumb aplumb at gmail.com
Wed Oct 13 00:18:12 UTC 2004

On Tue, 12 Oct 2004 15:04:23 -0700, Yan-Fa Li <yanfali at best.com> wrote:
> 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.

Thanks for the heads-up.  It's been a while since I powered up the
board; couldn't remember if it was i586 or i686, but it did run
Knoppix right off the CD. :-)

> 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. 

Will do.  My intent is to have the PVR-350 as the one-and-only card,
so it shouldn't be an issue.

> 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.

The X-board itself has audio, video (VGA and/or TV), ethernet, USB
already, so "all" that's needed is the interface circuitry off the
200-pin SODIMM connector.  What I'm aiming for is a backend-only
system whose only purpose is to capture A/V directly to disk, in the
case of a PVR-350 play it back, and serve up the recordings as-is via
network.  Everything else is icing...

Ah yes, I want to squeeze it all into a 5-1/4" footprint so I can
mount it in a CDROM drive bay.  ;-)  That may be a bit of a stretch,
so I'm willing to put the X-board+PVR-x50 in the 5-1/4" bay with an
external IDE connector to an HD mounted elsewhere...  Or I just might
skip the IDE interface all together and take advantage of the USB
interface so drives are hot-swappable...

First things first. :-)



If you don't know what to do, do something.

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