It will support all 100Mhz bus CPU's. Since the multiplier is locked on these CPU's, the memory will really let you know how fast you can clock it (as long as the CPU can take it).
I have a P3-700/100mhz running at 822mhz at the stock voltage(my current memory is the limiting factor)
Essentially, a FCPGA P3-850/100 is the biggest you can run, but have not seen any with that set up. I know for a fact that a FCPGA P3-800/100 works