[mythtv-users] MythTV system

Kim Wall kim at ductilebiscuit.net
Thu Dec 29 21:30:11 EST 2005

Lee wrote:

> Can't comment on the rest of the setup but the Avermedia 771's are 
> great, I run three of them in my Mythbox, fed from an external 4 way tv 
> distribution amp they work fine. All three recording, while playing back 
> a recorded show :)

Though they do seem to have issues with some motherboard chipsets - a 
friend's backend with a 771 was losing data on DVB recordings when the 
backend's PVR250 card was also recording (ie. generating lots of PCI 
traffic), or when there was a very high level of disk activity.  In the 
end (after faffing about with drivers, kernels, timings and the order of 
the PCI cards with little success) we swapped the Nforce2 based 
motherboard for an older one with a VIA chipset, which cured the problem 

Extensive googling suggested the problem is caused by a combination of 
the bt878 having an inadequately sized buffer, and the driver not 
getting the chance to service the IRQ quickly enough (presumably there's 
something about the Nforce2 that exacerbates this).

All this aside, I'm running a 771 myself (on an Asus A7V600-X 
motherboard, if anyone wants a known-good combination) alongside a 
PVR250 and have never had a problem with it.  The bt878 driver Just 
Works.  It's a good card which seems to have a more sensitive tuner than 
my DVB settop box.


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