LGA 1851 vs LGA 1700: What's the difference?

Intel has just unveiled its new LGA 1851 socket, a ground grid CPU socket designed by Intel specifically for Arrow Lake-S desktop processors and possibly other generations in the future.

It is therefore the socket that is intended for Intel's brand new desktop processors that use the new Intel Core Ultra x 2xx nomenclature.

Compared to the LGA 1700 socket, the number of pins has increased from 1700 to 1851, but it has the same dimensions and the same centre-to-centre distance for the mounting holes, ensuring compatibility with all LGA 1700-compatible CPU cooling systems.

It provides 20 PCIe 5.0 lanes (16 for the GPU and 4 for an M.2 PCIe SSD), plus 4 additional PCIe 4.0 lanes for a second M.2 PCIe port. The PCIe lines available for expansion cards (GPU mostly)can now be split into three (x8, x4, x4) instead of two (x8, x8) on the LGA 1700.

In terms of memory, it uses DDR5 exclusively, abandoning support for DDR4 unlike its predecessor (LGA 1700). Although not exclusive, its launch coincides with the arrival of CUDIMM and CAMM2 on the market.