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Re: performance problem

On Sat, 29 Jan 2005 09:59:10 -0500
Roberto Sanchez <roberto@familiasanchez.net> wrote:

> michael wrote:
> > On Fri, 2005-01-28 at 17:36 -0600, Ron Johnson wrote:
> >
> >>Could it be that your disk(s) aren't running in DMA mode?
> >
> >
> > how does DMA help? should this be on for all machines (eg mine!)?
> > thanks,
> DMA stands for direct memory access.  It allows capable drives and
> controllers to access memory while bypassing the CPU.  This means that
> since the CPU is not required to arbitrate every transfer to and from
> memory: a) they complete much faster, and b) your overall CPU load is
> significantly less.

I saw a significant difference with video playing performance. It doesn't sound
like your mouse problem, but could be the mp3 problem. It could also be some
problematic daemon. I used to have that problem with the cpufreq daemon (or
something similar) due to problematic access to the proc file system. It did add
some compatibility mode that was supposed to solve that.

Three things

Post the output of 'ps aux' we'll try to see if there is a potentially
problematic daemon running.

Check by running hdparm -d /dev/hda (and possibly /dev/hd[bcd] if you have more
hard disks and/or cdrom drives). It should show 'using dma = 1'. If it show 0
(off) try running hdparm -d 1 /dev/hda (or any other drive thats problematic).

Like some other else pointed out, with kernel 2.6 the X server should run at the
same run level as other programs. Check the previous mail about what package you
need to reconfigure to change the default nice level.

> -Roberto
> --
> Roberto Sanchez
> http://familiasanchez.net/~sanchezr

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