S2600BP Processor Socket Assembly

Skylake socket and processor parts

Unlike previous Intel® Xeon® E5-2600 (v3/v4) processors that use an integrated loading mechanism (ILM), the S2600BP motherboard includes two Socket-P0 (LGA 3647) processor sockets that supports Intel Xeon Scalable processors. The socket features a rectangular shape which is different from the square shape of previous sockets. The LGA 3647 socket contains 3647 pins and provides I/O, power, and ground connections from the motherboard board to the processor package. Because of the large size of the socket, it is made of two C-shaped halves. The two halves are not interchangeable and are distinguishable from one another by the keying and pin1 insert colors: The left half keying insert is the same color as the body, the right half inserts are white.

The LGA 3647 socket also supports both the Intel Xeon Scalable processors with embedded Intel Omni-Path Host Fabric Interconnect (HFI).

The parts of the socket assembly is described below and shown in the following figure.

Important: The pins inside the processor socket are extremely sensitive. No object except the processor package should make contact with the pins inside the processor socket. A damaged socket pin may render the socket inoperable, and will produce erroneous CPU or other system errors.

Processor Heat Sink Module (PHM)

The PHM refers to the sub-assembly where the heatsink and processor are fixed together by the processor package carrier prior to installation on the motherboard.

Processor Package Carrier (Clip)

The carrier is an integral part of the PHM. The processor is inserted into the carrier, then the heatsink with thermal interface material (TIM) are attached. The carrier has keying/alignment features to align to cutouts on the processor package. These keying features ensure the processor package snaps into the carrier in only one direction, and the carrier can only be attached to the heatsink in one orientation.

The processor package snaps into the clips located on the inside ends of the package carrier. The package carrier with attached processor package is then clipped to the heatsink. Hook like features on the four corners of the carrier grab onto the heatsink. All three pieces are secured to the bolster plate with four captive nuts that are part of the heatsink.

Important: Fabric supported processor models require the use of a Fabric Carrier Clip which has a different design than the standard clip shown in the figure below. Attempting to use a standard processor carrier clip with a Fabric supported processor may result in component damage and result in improper assembly of the PHM.

Bolster Plate

The bolster plate is an integrated subassembly that includes two corner guide posts placed at opposite corners and two springs that attach to the heatsink via captive screws. The springs are pulled upward as the heatsink is lowered and tightened in place, creating a compressive force between socket and heatsink. The bolster plate provides extra rigidity, helps maintain flatness to the motherboard, and provides a uniform load distribution across all contact pins in the socket.

Heatsink

The heatsink is integrated into the PHM which is attached to the bolster plate springs by two captive nuts on either side of the heatsink. The bolster plate is held in place around the socket by the backplate. The heatsink's captive shoulder nuts screw onto the corner standoffs and bolster plate studs. Depending on the manufacturer/model, some heatsinks may have a label on the top showing the sequence for tightening and loosening the four nuts.

There are two types of heatsinks, one for each of the processors. These heatsinks are NOT interchangeable and must be installed on the correct processor/socket, front versus rear.

Bolster Plate Insulator

The 3211 compute nodes include a bolster insulator plate on CPU 1 to prevent potential contact between a PCIe add in card (when installed) and the metal bolster plate assembly. The insulator should only be removed when installing a processor SKU that supports the Intel® Omni-Path host fabric interconnect (HFI). The insulator must be reinstalled after the setup is completed. Do not operate the compute node without the insulator when configured with a PCIe add-in card. Doing so may critically damage the PCIe add-in card, the motherboard, or both.