LGA 3647

LGA 3647 is an Intel microprocessor compatible socket used by Xeon Phi x200 ("Knights Landing"),^[1] Xeon Phi 72x5 ("Knights Mill"), Skylake-SP, Cascade Lake-SP, and Cascade Lake-W microprocessors.^[2]

LGA 3647

Release date	2016 (2016)
Designed by	Intel
Manufactured by	Lotes
Type	LGA-ZIF
Chip form factors	Flip-chip
Contacts	3647
FSB protocol	Intel UPI DMI 3.0 PCI Express
Processor dimensions	76.0mm × 56.5mm 4,294mm2
Processors	Knights Landing Knights Mill Skylake-SP Cascade Lake-SP Cascade Lake-W
Predecessor	LGA 2011
Variant	LGA 2066 (HEDTs and workstations)
Successor	LGA 4189
Memory support	DDR4
This article is part of the CPU socket series

The socket supports a 6-channel memory controller, non-volatile 3D XPoint memory DIMMs, Intel Ultra Path Interconnect (UPI), as a replacement for Quick Path Interconnect (QPI), and 100G Omni-Path interconnect and also has a new mounting mechanism which does not use a lever to secure it in place but the CPU cooler's pressure and its screws to secure it in place.

Variants

There are two sub-versions of this socket with differences also in the ILM (Independent Loading Mechanism, pitch of center screws changed slightly and a more visible one being that the guiding pins are in other corners). The processor socket and the matching notches on the processor are at different location, preventing insertion of an incompatible processor and preventing use of the wrong heatsink in a system. The more common P0 variant has two sub-options for heatsink mounting – designated as square ILM and narrow ILM, choice of which depends on the server and mainboard design (likely based on space constraints).

• LGA3647-0 (socket P0) used for Skylake-SP and Cascade Lake-SP processors^[3]
• LGA3647-1 (socket P1) used for Xeon Phi x200 processors^[4]

References

1. Alcorn, Paul (June 20, 2016). "Intel Xeon Phi Knights Landing Now Shipping; Omni Path Update, Too". Tom's Hardware. Retrieved November 14, 2022.
2. Alcorn, Paul (June 3, 2016). "Skylake Xeon Platforms Spotted, Purley Makes A Quiet Splash At Computex". Tom's Hardware. Retrieved November 14, 2022.
3. "Intel® Xeon® Processor Scalable Family: Thermal Mechanical Specifications and Design Guide" (PDF). Intel. December 2019. Retrieved November 14, 2022.
4. "Intel® Xeon Phi™ Processor x200 Product Family Thermal/Mechanical Specification and Design Guide" (PDF). Intel. June 2017. Retrieved November 14, 2022.