Intel Xeon X5355 2.66Ghz 1333Mhz 8MB BX80563X5355P SLAC4 Package Type:Retail BoxFamily:ClovertownProcessor Type:Intel Xeon X535564-bit Computing:YesCompatible Processor Socket:771-land FC-LGA6/mLGAClock Speed:2.66GhzBus Speed:1333MhzManufacturing Process:65nmCache Memory:8MB Features:Quad Core Enhanced Intel Speedstep Technology Intel EM64TIntel I/OAT Intel Virtualization Technology Enhanced Halt State (C1E) Execute Disable Bit Intel Thermal Monitor Compatible Slots:1 x processor - 771-land FC-LGA6/mLGACooling Device:HeatsinkOperating Temp.70C