[mythtv-users] video artifacts on recordings: could building a raid be the cause?

[jksj]

I have had what looks like the effect of poor signal on a recording, the 
same as described at the top of the thread. This occurred when writing 4 
HD channels to a SATA drive (not used by the database) and watching a 
different channel. Machine load was < 10%.
I know that when poor reception is the cause the backend logs the fact 
and marks the recording as failed. Frontend shows a red box round the 
program.
Is there any way of telling whether disk access time is causing a problem?
Anything logged?
Does the backend stall waiting is there a throw away mechanism. The 
other three simultaneous recordings were perfect.