[mythtv-users] best method to performance tune?

Charles Choukalos choukalos at yahoo.com
Thu Feb 6 19:28:29 UTC 2003


Brian,

I seem to recall you were on a PIII-450.  I have a
dual PIII-550 server running a lot of other functions.
 I finnally settled on mpeg at 320x240.  It sucks up
about 65% of 1 processor while the other is busy.  I
can't do 480x480 by any means.  I was playing with
jtjpeg... but I found it to take up way too much disk
space 9gb/hour and really killed my system compared to
the mpeg4.  Oh, I use default settings 2200 bitrate,
with the scale to size from 640x480 checked.  I have
tried upping the bitrate to 3300, but I didn't notice
a huge difference.  Now, please bear in mind that this
is my fileserver (.5 TB), and project box.  I have an
average load of 3 computers swapping files/and running
light cpu tasks with occasional spikes of high cpu
activity.  I nice my processes so myth is fine
recording (sometimes, I get stutter... but very very
very rarely).  I also have 2 gigs of RAM so that might
make some difference too as almost everything is
cached.  But this works for me.  

Hope this helps.

-Chuck
--- Jeff_Mitchell at accessbusinessgroup.com wrote:
> 
> Brian-
> 
> Well, you can probably get in the ballpark by
> looking at what other people
> are using for hardware and compression settings.  I
> had some posts
> yesterday talking about my setup (a search on the
> myth-dev archive for the
> strings 'Mitchell' and 'PIII' should get you on the
> right thread.  Even if
> my hardware is vastly different than yours, you
> should be able to ballpark
> what your box can handle.
> 
> For the tweaking after you're in the ballpark, I'd
> start by deciding which
> compression method you want to use.  I believe MPEG4
> takes more grunt, but
> gives you a larger file size, while rtjpeg is
> vice-versa (with
> middle-of-the-road quality settings -- I'm sure you
> could switch this
> around by screwing around with settings.)  Then look
> at resolution, and
> finally the compression settings.
> 
> Before starting this, you should brobably psyche
> yourself up for a
> (possibly) lengthy, iterative process.  Because
> "quality" is such a
> subjective, nebulous term, you're not going to find
> a straight answer for
> video settings.  Just use Myth like you plan to use
> it, and play around
> with settings until you find something that works
> for you.  I played around
> with the seetings for a few days, and haven't
> touched them since.  Perhaps
> I'll get the bug, but probably not any time soon. 
> Obviously after a
> hardware upgrade, I expect to go through the same
> rigamarole.
> 
> During your journey, if you have any questions about
> how you might be able
> to tweak something specific (like problems during
> panning, etc.), you could
> probably get some good insight from this list.
> 
> -Jeff
> 
> P.S.  I should note that I had played around with
> settings for the same
> card on a pretty much comparable machine under
> Windows XP before, and I did
> that for probably 3-4 days, so I had a bit of a head
> start when configuring
> the compression settings for Myth.
> 
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at snowman.net
> http://www.snowman.net/mailman/listinfo/mythtv-users


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