The Intel Xeon W5580 was a server/workstation processor with 4 cores, launched in March 2009, at an MSRP of $1600. It is part of the Xeon lineup, using the Gainestown 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 W5580 CPUs can work together in a multi-processor (SMP) configuration. Xeon W5580 has 8 MB of L3 cache and operates at 3.2 GHz by default, but can boost up to 3.466 GHz, depending on the workload. Intel is making the Xeon W5580 on a 45 nm production node using 731 million transistors. The multiplier is locked on Xeon W5580, which limits its overclocking potential.
With a TDP of 130 W, the Xeon W5580 consumes a lot of power, so good cooling is definitely needed. Intel's processor supports DDR3 memory with a triple-channel interface. The highest officially supported memory speed is 1333 MT/s, but with overclocking (and the right memory modules) you can go even higher. 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 system, Xeon W5580 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 W5580, which greatly improves virtual machine performance. Additionally, IOMMU virtualization (PCI passthrough) is supported, so that guest virtual machines may directly use host hardware.