The Dell Poweredge R640 server can hold quantity two 2nd Generation Bronze, Silver, and Gold processors. If installing a second processor make sure to use a genuine Dell heatsink. It has been specifically engineered for the Poweredge R640.The heatsink for the Poweredge R640 can be found in the heatsink category. When installing the processor make sure to put thermal paste between the processor and heatsink. If you have any questions on the Poweredge R640 Processor kits give us a call at 952-831-1032.