The Intel Xeon E5640 was a server/workstation processor with 4 cores, launched in March 2010. It is part of the Xeon lineup, using the Westmere-EP architecture with Socket 1366. Thanks to Intel Hyper-Threading the core-count is effectively doubled, to 8 threads. To further increase overall system performance, up to two Xeon E5640 CPUs can link up in a multi-processor (SMP) configuration. Xeon E5640 has 12 MB of L3 cache and operates at 2.666 GHz by default, but can boost up to 2.933 GHz, depending on the workload. Intel is building the Xeon E5640 on a 32 nm production process using 1,170 million transistors. The multiplier is locked on Xeon E5640, which limits its overclocking capabilities.
With a TDP of 80 W, the Xeon E5640 consumes a good deal of power, so decent cooling is needed. Intel's processor supports DDR3 memory with a triple-channel interface. ECC memory is supported, too, which is an important capability for mission-critical systems, to avoid data corruption. For communication with other components in the machine, Xeon E5640 uses a PCI-Express Gen 2 connection. This processor lacks integrated graphics, you might need a graphics card.
Hardware virtualization is available on the Xeon E5640, which greatly improves virtual machine performance.