I am a community college networking stundent and am looking for a server to practice with. I was recently presented with a decision on what CPU i should use for my project server. I was confused on whether to choose a machine with a Pentium III Xeon CPU or a regular Pentium III CPU. I know that the Xeon has some advantages over the regular pentium but how much of a difference does it make in processing power between the 2. I would greatly value any advice

Really depends on the version of Xeon or P3 that you use. The difference is really in the cache.

Some versions of the Xeon had massive L2 caches of up to 2MB.
Avoid Tanner xeons: as large as the caches were on these, they were off-die (slower).

Cascades Xeons have anywhere from 256KB-2MB of on-die cache. If you can get your hands on a Cascades Xeon with 1 or 2MB, use it. If it's only a 256K or 512K version, just grab a standard Coppermine-based P3.

As far as P3s go, avoid Katmai-based P3s like the plague. These were barely any faster than P2s, because of a half-speed off-die cache.

Coppermine P3s are OK. They're everywhere, making them cheap. Unless you can get a Cascades Xeon with over 512KB of cache, stick with the Coppermine Pentium III.

Tualatin P3s rock! The "S" version of the Tualatin P3 has 512KB of super-fast cache, and feature data prefetch capabilities. At 1.4GHz, these P3s are as fast as P4s at 2.2GHz. If one of your choices is a Tualatin P3, grab it! They're better than any of the Xeons. The 512K version of the Tualatin P3 should even outperform the fastest of the 2MB Cascades Xeons, thanks to higher clockspeed, more advanced architecture, and faster bus speed.

Pentium III--Descendant of Intel Core.
Pentium III-S 1400 @ 1.63GHz, 512K L2
X800XT AIW OC 580/600
2GB of RAM
250GB HD
SB Audigy 2
QDI Advance 12 mobo
Smugly running Vista