You can....
unfortunately, distros like Mandrake/Fedora come with a lot of stuff, a lot of which could hurt your need for speed.
There are things like Damn Small Linux (
www.damnsmalllinux.com) which you can play with... you could also see how well the machine handles xwindows/windowing programs with something like Knoppix (
www.knoppix.org), which runs completely off the CD.