Entry-Level Power Supply Specification (abbreviated EPS) is a Power Supply Unit meant for high end computers and entry-level servers. Developed by the Server System Infrastructure forum (which is a group that works on server standards), the EPS form factor is a derivative of the ATX form factor. The EPS standard provides a more powerful and stable environment for critical server-based systems and applications.
Power supplies built to the EPS standard include a 24-pin motherboard power connector and an 8-pin +12V connector. The standard also specifies two additional 4 pin 12V connectors for more power hungry boards (one required on 700W-800W PSUs, both required on 850W+ PSUs) . EPS power supplies are in principle compatible with standard ATX or ATX12V motherboards found in homes and offices but there may be mechanical issues where the 12V connector and in the case of older boards the main connector overhang the sockets. Many PSU vendors use connectors where the extra sections can be unclipped to avoid this issue. As with later versions of the ATX PSU standard there is also no -5V rail.
The latest specification is v2.92.