800 seems to be about the fastest that I can find on webpages also.

I have an older Compaq Proliant 1850R that has dual PIII 550mhz slot 1 cpus... and I wanna upgrade them. I should probably look to see if the board in there will support that high.

I also have a router/gateway/firewall at my parents house that has a PIII 533mhz slot 1 and I wanna upgrade that too.