I'm running a Slot 1 SECC1 PII 400@496 , with stock heatsink and double fans..I figure its one helluva oc for this kinda cpu..mobo is EPoX 61BxA-M.Runs at 36-38 C depending on load. (temps taken using the thermal diode, in Epox's USDM thingy for measuring the temps, voltages, and fan speeds.)