If you're using Linux, you will also want to do fun stuff with DMA as well, as enabling this will significantly speed up your hard drive access speeds. However, this being Linux, it's not quite as easy as "tick a box". You need to instead get acquainted with the hdparm command. There's lots of different stuff that you can do with this to improve IDE performance, but for DMA you need to do the following:-

hdparm -d1 <drive name>
e.g. hdparm -d1 /dev/hda
(for obvious reasons you're going to need to be root for this!)

This needs to be done on each bootup, so I'd advise putting it on your /etc/rc.d/rc.local or similar (depending on your particular distribution)