[mythtv-users] Multiplexing vs multiple cards

[Greg Oliver]

On Thu, Nov 4, 2010 at 5:28 AM, Anthony Giggins
<seven at seven.dorksville.net> wrote:
>
>
> On 4 November 2010 16:03, Christopher Kerr <mythtv at theseekerr.com> wrote:
>>
>> On Thu, Nov 4, 2010 at 4:13 PM, Paul Buchanan <paul.buchanan at gmail.com>
>> wrote:
>> > I'm using hardware that I've rescued from various sources to make one
>> > master
>> > and one slave.  3ghz and 2.8ghz P4 CPUs.
>> > Quite old I know ... so I'm trying to manage the load as best I can with
>> > config tweaks.
>>
>> Ah, fair enough - hot, power hungry, and pretty weak by todays
>> standards. I have a P4 3.0GHz under my desk as a footrest - I suspect
>> it has worked its last day ;o)
>>
>> I'd suggest you limit the system to 2 simultanous jobs and see how you
>> go - real time commflagging isn't as CPU intensive as it might be,
>> because it's capped at the framerate of the incoming video.
>>
>> Oh, and make sure you make life as easy as you can for it - put the
>> database on a different disk to the recordings, and spread your
>> recordings directories over 2+ disks too, if you can - made a huge
>> difference to my (rather more powerful) system - with 3 harddrives, I
>> can now record 6 programs (typically 5 SD and 1 HD, given how little
>> real HD content we get here) with commflagging whilst playing a
>> recording on a seperate frontend - I've never tried winding up both
>> frontends at once on a Saturday night, but I suspect it'd handle it.
>>
>> - Chris
>>
>
> I'd even go as far as limiting the simultanous jobs to 1, especially if you
> ever export recordings, my P4 3.0GHz seems to run fine now I fixed my
> thermal throttling issues thanks to some suggestions from the list but I am
> using a nvidia GT240 to offload alot of the display processing to the GPU.

I have found that real-time comm-flagging (up to 6 simultaneous) is a
lot less intensive on the system than playing catch up.  Of course if
you don't mind waiting a day for your stuff, then you can use low
priority and just let it run overnight.  I watch my shows after they
run daily though.

6 jobs on an 8 thread processor running with the recordings is a lot
less stressful on the disks than running them afterward though (which
in turn keeps the system out of IO wait and the CPU much more idle as
well)..

Commflagging afterward really stresses my sytsem.  Not that it cannot
do it, but I use the system for work as well, so I like it to be as
responsive as it can.