[mythtv-users] Problems with multiple pvr cards
Brian L. Walter
blwalter at gmail.com
Wed May 9 10:09:23 UTC 2007
Karl E. Jorgensen wrote:
> On Tue, May 08, 2007 at 08:31:28PM -0400, Brian L. Walter wrote:
>> I've got 1 pvr-500 and one pvr-150, running ivtv 0.10.1 with myth
>> 0.20-fixes as of 5/6.
>> I have run a couple 30 minute cat /dev/videoN against all 3 devices
>> simultaneously, with no problem.
> Was this a simple "cat /dev/videoN > /dev/null" or did the output go to
>> However, when Myth goes to record on all 3, I start getting ENC DMA
>> Errors, anywhere from immediately to 20-30 minutes.
> Obviously, myth writes to disk :-)
>> I've read that there is an interrupt issue with the 0.10.1, and was
>> wondering if this is a result of that issue.
> Could be. But you need to take the total load of the box into account -
> so myth's disk activity may become significant.
>> This problem does not occur when only 2 of the three inputs are in
>> use, only with all three. The only way to clear it up is to reboot,
>> because this situation will eventually lead to dma timeouts, and
>> driver not responding....then...system crash.
> If your tests before did not write to disk, try some that do. If the
> to-disk tests produce DMA errors whereas the not-to-disk ones do not,
> then the disk activity is significant (but not necessarily the cause).
> Then it would be time to try things bonnie++ (without touching the PVRs)
> to elimiate disk DMA problems...
> Hope this helps
Thanks for the tips.
The cat's where to disk...so it's as close (I hipe) to mimicking what
myth does without using myth.
I was beginning to think disk - and latency. However, it appears you
can't change the latency on this motherboard (or least, not without
calling Asus support - guess I'll have to sit in the queue for a bit :) ).
Do people have 'recomended' settings for the PVR's in terms of
recording profiles? Again, I saw something on the IVTV site that
implied that resolution needs to be 720x480...and was wondering if the
bit rates figure into this too...
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