yes this is a broad statement, but should be helpful to others building new boxes.
My shuttle SK41G uses the VIA KM266 chipset and due to a bug in the northbridge, high bandwidth DMA operations cause recordings to crash when you begin watching another recording.
This behavior has been seen with the KT133 chipset, as well as VIA based chipsets for Intel processors as well.

At this point you may try to apply a BIOS upgrade to see if the bug has been worked around in the BIOS.

For anyone building a KnoppMyth or MythTV box, avoid using VIA chipsets. They are full of bugs.

For AMD based systems, get a SiS, nVidia, or AMD based motherboard.
For Intel based systems, you can't go wrong with an Intel chipset.

Please do not take this thread as a flame starter, I am just very dissappointed that I had to waste $160 on this barebone box and I can't do something very basic due to a crappy bug that VIA has neglected to fix.

Hey if they will actually record the guys over at the ivtv camp have been doing some good work. when I tried a pvr250 with a via based MB I couldn't even record for more than like 2 min before the dma bug crashed it.

I just thought I would share my experiences on this front as I have been struggling with the VIA chipset for a while as well. I tried various combinations of things to fiddle and I eventually achieved some degree of stability by doing the following:

1) removed my old Firewire card
2) Changed the bios to a non-PNP enabled OS
3) Turned off the paralell port in th BIOS
4) Sacrificed a small rodent on the keyboard.

Obviously there is some degree of uncertainty here as to what is helping (I also tried disabling various other bios options and fiddling with the hdparm settings, but wound up restoring the defaults).

So far I have not had any issues wathing TV - something that was at best a 50/50 affair under the previous config. The only problem I seem to have is that I can't start a recording while the onscreen guide with the shrunken live window is up (although that may not a HW issue - as I can schedule and instantly start recordings through other interfaces.) That pretty much crashes the back-end and I have to manually restart it.

Anyway - just thought I would share.
Peter.

Config:
--------
MySettopBox R4V2
AMD Athlon XP 1700
Haupauge PVR 250
Shuttle K32A Motherboard (VIA KT266)
ATI 7200 Graphics card.

PS: Thank you to everyone who has posted to these boards- it's been a real help resolving all the other little config problems that come up.

I have the same Barebone...
my total hardware exist of the following

SK41G
AMD 2200+
Kingston 2x256 MB DDR
hitachi 80GB 8mb 10000
Liteon dvdplayer
Hauppauge pvr 350


installation worked without a problem,
unfortunattly i cannot get the SVideo of the PVR to work
the only output which i get some signal on is the svideo of the barebone
2nd i'm only able to see 1 quarter of my screen ? resolution problem...

on a different HDD based on windows ( the other OS) myhtpc.net,showshifter,gbpvr worked all nicely,
but i want this to work

What are you outputing to from S-Video? TV/Monitor/HDTV?

I never had that problem with S-Video outputing to only 1/4 of the screen.
What installation options did you choose?

My box has a VIA chipset KT266A / VT 8235
on a PCChips M811LU
Athlon XP1800
and PVR-250

And mine works great, so its not all via chipsets but I would agree is saying go with nforce, or SIS.

Demon,
What quality levels do you have set for recordings?
I have mine set to 720x480, 4400Kbps and the bug hits almost like clockwork.

Do these problems extend to the KT133A chipset? I just noticed the old board I was planning to use is of this chipset.

I believe that the KT133 chipset is where this bug first appeared.

I had a kt133 board and it wouldn't even start to record because of this bug.

I have a KT133 board. I have run into some trouble trying to get a new PVR250 to work on KnoppMyth but before buying that card I was able to record with an Osprey 200. btaudio is what gave me the trouble with that setup . Could these issues be related to PVR + VIA hardware conflicts?

the problem is related to high bandwidth DMA operations.

I can record fine with my box, but recording and playing back at the same time is what causes the problem for me.

I installed an add-on IDE Controller to try to overcome this problem. This was a little tricky to setup initially because the new controller would not let me boot from a CD. So I left the primary IDE channel open on the mobo for the CD-ROM , and close the second IDE channel on the mobo. I put the boot HD on the primary off board IDE channel. This allowed me to boot off of the CD to install Knoppmyth but still have the HD on the new IDE so that DMA would work.

Then I did a manual install of KnoppMyth. The system is now mostly up (I have some lingering sound difficulties) and its definately more stable. Watching live TV is more fluid and less prone to freeze ups. Still it's not perfect.

Adrian

I should have also mentioned, that DMA is working fine on the new card (I used an SIIG Utra DMA 100). Whatever performance issues that remain could be due to the video drivers....

I can only confirm the troubles with VIA chipsets under Linux. Used a KT133 board first, but had to dump it, too many problems and lockups. The disconnect bug was the least one (the CPU doesn't go into powersave mode, i.e. is heating up like crazy even while idle. I think it's even present on KT266 ), that could be fixed with a small prog called athcool, but then onboard audio wasn't working anymore...

Moved to a KT600 board, even worse, see KT600 thread...

Now I'm using a KT400 based board and things start looking better, except frequent seg faults caused by mythbackend. Oh well, one last complete re-installation and if it doesn't help I switch to Intel and never look back.

Consider yourself lucky if your VIA system works rock solid - rebooting a server once a day is not an option...