[mythtv-users] Software changes required when switching CPU from single-core to multi-core?

[Raymond Wagner]

On 5/25/2011 08:26, Craig Huff wrote:
> Was there something I was supposed to do to tell MythTV that this is
> now a multi-core BE?  IIRC, MythTV -- at least in the version I'm
> running (MythTV Version   : 24158; MythTV Branch    :
> branches/release-0-23-fixes; AKA MythBuntu 10.04)  only supported
> single-threading anyway.

MythTV runs multiple processes, and each of those processes has multiple 
dozen threads, and among those threads there are multiple independent 
pathways not locked under shared mutexes.  What you may be thinking of 
is software video decoding, which is limited to single threaded 
operation by the decoding libraries, ffmpeg.  Even that is not entirely 
true, because multi-sliced h264 can be decoded in multiple threads, and 
the decoding profiles default to two threads in this case.  That is the 
_only_ option pertaining to threading that you can control in MythTV

The Athlon 64 3200+ is a 2GHz socket 939 chip.  The Athlon 64 X2 3800+ 
is a 2GHz dual core socket 939 chip.  You do not have an Athlon II, as 
that is a whole new architecture with a whole new incompatible socket.  
Your new chip is exactly as fast as your old chip in single threaded 
operations, and aside from some shared resources like memory and bus, 
should have roughly double the performance on multi-threaded operations.

You are running an unstable version of MythTV on the 0.23-fixes branch, 
several hundred revisions prior to stable release.  This may very well 
be causing a number of your problems.  Other possibilities could be a 
nearly full hard drive for either recording, or database storage, or a 
damaged database that is causing excessively long queries when under 
heavy recording load.  It should be completely independent of your CPU 
swap, which is likely to have just coincidentally happened at the same 
time these problems started to appear.