Socket TR4, also known as Socket SP3r2, is a zero insertion forceland grid array (LGA)CPU socket designed by AMD supporting its first- and second-generation Zen-based Ryzen Threadripper desktop processors,[1][2] launched on August 10, 2017[3] for the high-end desktop and workstation platforms. It was succeeded by Socket sTRX4 for the third generation of Ryzen Threadripper processors.
TR4 is AMD's second LGA socket for a consumer product after the short lived Socket 1207 FX.[4][5] It is physically identical to, but electrically incompatible with both AMD's server Socket SP3, and TR4's successor, Socket sTRX4.[3][6]
While the SP3 server socket does not require a chipset, instead utilizing a system-on-a-chip design, TR4 and its successor HEDT sockets require a chipset to unlock the features of the CPU. For TR4, the AMD X399 chipset was released, which allows a total of 64 PCIe 3.0 lanes for quad SLI/CrossFire configurations.[7]