Any benchmarks on Fluent for a Pentium III chip against a Pentium-III-xeon chip (at the same speed) ?

Yep, when we bought our old Linux cluster almost 2 years ago we benchmarked Xeon 500 MHz machines (Dell Precision 610) against PIII 500 MHz machines (Dell OptiPlex GX1). The speed difference was very small, almost negligable. I would guess that the same is true today, although the higher clock-frequencies available today might make the faster cache on the Xeons more important. If you are about to buy you might want to wait for the P4s to be launched anytime now.

Hy, did you look on the fluent-homepage ? They also have benchmarks there.