The MPC Pro^® S-5615D Desktop is designed for optimal performance with workstation-class configurability. Benefit from the top-notch level of performance and features, including genuine Microsoft^® Windows^® XP Professional Edition, the latest Intel^® 975X chipset, OpenGL graphics, ultrahigh-speed hard drives, ECC or non-ECC memory and RAID options. Complementing these high-end features is BTX Technology with ultraquiet dual fan cooling for improved reliability.