Mac OS X has both the nice and renice commands installed. (renice is used to 'nice' a
running application.) Strangely, related commands getpriority and setpriority don't
seem to work.

I haven't yet figured out where the System keeps its startup shell scripts, so I'm not
sure how to nice the filesharing process at boot time. You can do it once the system is
up by typing:
sudo renice +5 <PID#>
where <PID#> is the Process ID, which you can get from "top". This will only work until
the machine is restarted. Here I've added 5 to the priority.

Priorities range from -20 to 20, 20 being lowest. Most everything is (and should be) priority
zero.

I have to say I'm a little mystified that people are blaiming filing sharing for OS X's
performance problems. My AppleFileServer process just sits there; I threw 70 MB of quicktime
video at it a few hours ago, and it used up 13 cpu seconds while handling them. Since then,
it's used just 2 more cpu seconds. This doesn't look like the cause of a performance problem to me.

-rob