[mythtv-users] General ways to fix lag on liveTV

[George Mari]

Jonathan Seawright wrote:
> Hey all,
> 
> When I try to watch LiveTV on my mythTV box, I get visual skipping and nastyness. Whenever there is a recording seperately, playback is FLAWLESS, especially in HD content.
> 
> My system specs are as follows:
> AMD64 3000+ (running in 32bits mode)
> 1GB DDR
> roughly 400GB of space, split via LVM between an ATA 120gb drive, and a SATA 300gb drive.
> pcHDTV 5500
> 
> Any ideas on how to speed this up? It seems that after a bit of pausing or rewinding, I can watch it with little to no disturbances. It seems to me, that it is a buffering problem? Or simply the speed of the drives? I know for a fact that the ATA drive is filled... so we're recording to the SATA...
> 

Have you run top while playing back live TV?  Is your CPU maxing out 
under live TV?  My guess is no, but it's good just to be sure.

IMO, it's more likely you have I/O contention.  Do you have only the 
recording files on the LVM?  If if also contains the MySQL files, and 
the directory that myth logs to, that's two more things that are taking 
up your available I/O.

Do you have the same skipping when watching previously recorded content 
and recording another show simultaneously?  That would be another good 
data point to work from.

Try temporarily turning off logging on both the front end and back end 
to see if this improves things.
This made a difference for me when I had fewer drives in my system, 
until I separated things a bit more.

--
George Mari