The Intel Xeon E5-2403 is a server/workstation processor with 4 cores, launched in May 2012. It is part of the Xeon E5 lineup, using the Sandy Bridge-EN architecture with Socket 1356. Thanks to Intel Hyper-Threading the core-count is effectively doubled, to 8 threads. To further increase overall system performance, up to two Xeon E5-2403 CPUs can work together in a multi-processor (SMP) configuration. Xeon E5-2403 has 10 MB of L3 cache and operates at 1800 MHz. Intel is making the Xeon E5-2403 on a 32 nm production node using 1,270 million transistors. The multiplier is locked on Xeon E5-2403, which limits its overclocking potential.
With a TDP of 80 W, the Xeon E5-2403 consumes a good deal of power, so decent cooling is needed. Intel's processor supports DDR3 memory. ECC memory is supported, too, which is an important capability for mission-critical systems, to avoid data corruption. This processor lacks integrated graphics, you might need a graphics card.
Hardware virtualization is available on the Xeon E5-2403, which greatly improves virtual machine performance. Additionally, IOMMU virtualization (PCI passthrough) is supported, so that guest virtual machines may directly use host hardware. Programs using Advanced Vector Extensions (AVX) can run on this processor, boosting performance for calculation-heavy applications.