[mythtv-users] CPU Utilization Revisited

[Dan Robichaud]

I noticed something rather interesting last night as I was doing 
some testing at various resolutions and compression levels.

I kept hearing people talking about seeing CPU utilizations of 
4-9% for mythfrontend while watching live TV while whenever I 
looked, I was seeing more along the lines of 25-35% and was 
beginning to wonder whether I had X set up properly, etc, etc... 
(My X process also tends to eat up a lot of CPU - 20+ %...) 

Last night while experimenting with different compression 
settings and with top running from a telnet session on a 
different box, I noticed that my CPU utilization for X and 
mythfrontend noticeably dropped off (to 6-10%) once it had been 
up and running for a few minutes.  "Great!" I thought, "It's only 
on startup where it needs to consume a little more CPU to get 
things started up!"  But then I noticed over a long period of 
time that it would fluctuate back to those 30% levels again and 
then eventually back down to around 6% again.  Can anyone explain 
why this is?  I've also tried this in a lightweight windowm 
manager (fvwm2), but I get the same behaviour...

I suppose I should also mention a little about my hardware/setup:

MythTV 0.8 on RedHat 8.0
Abit KG7 RAID MoBo
AMD 1500+ XP
512 MB RAM
2 x Maxtor 120GB drives in RAID0
SBLive! 5.1
ATI TV Wonder
ATI AIW Pro video card

Not sure if it's related, but I should probably also mention that 
I tend to use RTJPEG settings at 480x480 (150-170 quality 
setting) because I find that the results are far better than 
MPEG4 when viewed on my 53" inch screen (I discuss this in 
another thread I just emailed out 5 minutes ago...)

Dan Robichaud