[mythtv-users] System Load/Performance Question

[Jonathan Lin]

what is your system load avg?  also check your interrupt.  I have an AMD 64 
box here running gentoo 2.6.15-R5 with 3 different tunners and I only 
encounter problem when the mythcomflag is running against my HD recordings. 
(my system load avg shoots up to 7).  Now I enable XvMC and I no longer have 
skippings, but then my situation is with HD and not SDTV.

On Sunday 19 February 2006 17:20, Brian Wood wrote:
> I know the "can this system do <blank> has been done to death here,
> but I need some comparisons.
>
> The system is an amd64 3700, running Gentoo 2.6.15, MythTV
> 0.18.1,1.5GB RAM
>
> We are talking strictly about SDTV here.
> 2-PVR-150s
> GeForce-5700 video card w/256MB.
> nVidia 7676 drivers, no XvMC, MythTV compiled with OpenGL support
>
> Recordings are going onto 2-250GB SATA drives configured Linux kernel
> software RAID0, JFS filesystem.
> Ring Buffer is going onto a UDMA 133 250GB single drive, JFS
> filesystem, no other drive on the IDE channel, The OS is on another
> partition of this drive.
>
> If I have a recording happening on tuner 1, and am watching LiveTV
> from tuner 2, and have a commercial flagging job happening, I get
> digital breakup on the live picture, and occasional breakup in the
> recording.
>
> Without a flagging job running there is no breakup on liveTV or the
> recording.
>
> CPU usage shows about 30-35%, no swapping is happening.
> The priority of the flagging job in MythSetup is set to "low".
> vmstat shows "WA" as "1", and very occasionally "2"
>
> So, my questions:
>
> Is this normal, am I simply asking too much of the system?
> Is it a disk IO problem? (I don't think it's a CPU problem)
> Would putting the ringbuffer on the RAID system help?
> Would moving to a SCSI disk system help?
> Should I just run flagging jobs at other times?
> Is having the ringbuffer on the same drive as the OS a bad idea?
>
> Obviously I'd like to figure out what the weak link is in this system
> that is causing the breakup, any ideas appreciated.
>
> Brian Wood
> beww at beww.org
>
>
>
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-- 
Jonathan Lin

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jonlin at linsvilla.com
http://gallery.kegogi.com
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