Depending on your situation, there are a number of possibilities here. As root, issue the 'chkconfig --list' command. This will list all of the services being started on your computer during bootup. There are some that you could disable in order to shave a few milliseconds. Kudzu is the RH hardware monitor, detecting when new hardware is installed or hardware is taken out. If you dont plan on reinstalling anything (or are capable of doing it manually), you can disable it. hooking this up to a printer? if not, disable lpd. You can turn off any network services that you dont need; httpd, nfsd, nfslock, pppoe, ypbind.
first, figure out what runlevel you currently boot into. then use the command:
'chkconfig --level <x> <package> off'
Like 'chkconfig --level 3 httpd off' would turn off httpd as long as you boot into runlevel 3. use the 'runlevel' or 'cat /etc/inittab' to find out your runlevel.
You can also look at the hard drive speed with hdparm to see if dma is turned on or not. '/sbin/hdparm -i /dev/hda' will give some good information for that. man hdparm for more info.