The Intel Pentium III Xeon 866 5V-12V was a server/workstation processor with 1 core, launched in April 2000, at an MSRP of $826. It is part of the Pentium III Xeon lineup, using the Cascades architecture with Slot 2. To further increase overall system performance, up to two Pentium III Xeon 866 5V-12V CPUs can work together in a multi-processor (SMP) configuration. Pentium III Xeon 866 5V-12V has 256 KB of L2 cache and operates at 866 MHz. Intel is making the Pentium III Xeon 866 5V-12V on a 180 nm production node using 28 million transistors. The multiplier is locked on Pentium III Xeon 866 5V-12V, which limits its overclocking potential. With a TDP of 25 W, the Pentium III Xeon 866 5V-12V consumes only little energy. The highest officially supported memory speed is 133 MT/s, but with overclocking (and the right memory modules) you can go even higher. This processor lacks integrated graphics, you might need a graphics card. Many games will refuse to start on this processor due to the lack of the SSE2/SSE3/SSE4 instruction set.