[mythtv-users] Reducing system resources (cpu, memory)

[Tom Marshall]

On Wed, Feb 25, 2004 at 08:40:51AM -0800, Donald McLennan wrote:
> Hi,
> I have MythTV running on a 450Mhz computer with
> PVR-250. Like other users with similar low end
> configuration, Mythtv works, but is slow.

I have a similar setup (466 celeron, 320MB, PVR-250) and I have MythTV setup
to run acceptably.

> Are there any suggestions on minimizing the cpu and
> memory requirements by disabling various linux
> services to get any better performance? What are the
> minimal linux services that need to be running? 
> 
> Are there any key MythTV settings like picture size,
> resolution, etc., that would improve performance?

How much memory do you have?  MythTV seems to love memory -- I'm even
considering upgrading to 512MB.  I don't think disabling services will gain
much, but it can't hurt either.

Here's some suggestions:

  - I use 480x480 resolution, 3000avg/6000max bitrate.  Lower bitrates don't
    seem to work well, the playback is frequently choppy.  Commercial
    flagging is just barely faster than realtime with these settings.

  - Use extra audio buffering to avoid choppy playback with dark scenes.

  - Add the "-framedrop" option to your mplayer commands so that video and
    audio stay in sync when the system can't handle the load.

> Would a PVR-350 card make any difference?

I don't have one of these, but I believe it would reduce your system load
dramatically during playback as it handles the MPEG2 decoding in hardware. 
Beware, though, this feature has many potential drawbacks (see the list
archives for details).

> Or, as others have commented, do I need a faster cpu?

That always helps... if you are willing to spend the money...  :-)

-- 
Perfection in design is achieved not when there is nothing left to add, but 
rather when there is nothing left to take away.                          
        -- Antoine de Saint-Exupery
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