CEB (from the English Compact Electronics Bay ) form factor server motherboards . Dimensions: 305mm x 267mm (12 "x 10.5"). The standard was developed in 2005 jointly by Intel , Dell , IBM and Silicon Graphics, Inc. as part of the SSI Forum  , the latest version of the 1.1 standard is described in the Compact Electronics Bay Specification.
- CEB 1.0
- CEB 1.01
- CEB 1.1
The CEB specification is intended to define the basic design of the form factor of servers and workstations. It also provides design solutions for temperature control and electromagnetic interference limitation. The specification defines the following properties:
- Maximum board size and mounting hole locations;
- Wiring of power connectors and signal connectors;
- Dimensions and layout of the I / O ports panel;
- Board / processor mounting requirements.
The CEB specification evolved from the EEB ( Entry-level Electronics Bay ) and ATX (form factor) specifications and solves the following problems:
- Support for dual-processor solutions for current and future processors, chipsets and memory module standards;
- Definition of power connectors optimized for high voltage and compatible with Electronics Bay power supplies;
- Identification of volume limitations and airflow movement strategies that simplifies the design of the enclosure, eliminates the problems of the mutual influence of components, and helps ensure proper cooling
- Increased interchangeability of boards and cases to reduce the time to market a new product;
- Reducing the cost of materials, production and development;
- The flexibility of mass production, allowing integrators to delimit and add components to rack and tower form factors .
The CEB board has the same mounting holes as the ATX board specification 2.2. and the same 24-pin main power connector This solution allows you to maintain compatibility between ATX boards and server platforms. CEB specification includes rear I / O ports identical to ATX specification
The CEB platform complies with the temperature design philosophy for tower enclosures, including four specific temperature zones (parts) inside the enclosure:
- Zone 1 is the main part of the motherboard including processors and memory modules. Depending on the configuration of the system, this area may include hard drive drives. Recommended cooling: two 120 mm front and rear fans.
- Zone 2 is part of the peripheral expansion cards, includes PCI and PCI Express cards, as well as video cards. Depending on the configuration of the system, this area may include hard drive drives. Recommended cooling: one 92 mm or 120 mm fan
- Zone 3 contains a power supply and typically includes external devices such as optical drives. Recommended cooling: internal power supply fan.
- Zone 4 consists of indicators and ventilation for the entire enclosure.
Functionally, the motherboard is divided into two parts: the base (main) part, where the processors and RAM are located, and the part where the expansion cards are located. The numbering of slots for expansion cards goes from the left edge of the board to the right (see. Figure). The design of the location of the processors and the numbering of the RAM slots are left to the discretion of the motherboard manufacturer.
There is a logical contradiction in the specification, apparently introduced for marketing reasons, namely: despite the fact that the specification assumes a free choice of the location of the processors, the Processor Mounting Holes section does not have a Recommended status, but a mandatory ( "Required"). Moreover, the distance between the mounting holes of the processor cooling system clearly corresponds to Socket 771 .
- CEB Specification v1.1 (link unavailable)