The Socket 939 is a central processing unit (CPU) socket that semiconductor manufacturer Advanced Micro Devices (AMD) mainly created for its Athlon 64 microprocessors. Like other CPU sockets, it serves not only as an electrical connection of the CPU with the motherboard of a personal computer (PC), but as a firm physical support mechanism to protect the chip from potential damage. The Socket 939 is significant for being the second socket that AMD created for its processors that use the AMD64 instruction set. Production lasted from June 2004 to November 2008, by which time it had been replaced by Socket AM2.
When AMD introduced the socket, the company named it after the number of pin holes it has. These contacts are meant for connecting the pins of the CPU and have a pin pitch of 0.05 inches (1.27 millimeters). Socket 939 uses the organic pin grid array (OPGA) layout, which means that the pin contacts are neatly arranged in a grid on a square-shaped substrate made of organic plastic. Socket 939 uses zero insertion force (ZIF), which means that it requires absolutely no force during the CPU’s insertion or removal. This feature is applied to prevent damage to the chip.
The Socket 939 made its debut as a desktop PC replacement for the Socket 754. Introduced the year before, in 2003, Socket 754 was the first AMD64-compatible socket. It had 185 less pin holes than its immediate successor. AMD was unimpressed with the sales figures of Socket 754, although the company retained it for laptop PCs until it replaced it with Socket S1 in 2006.
The main processors made for the Socket 939 were members of the Athlon 64 brand, which are so named because they are 64-bit processors. Debuting in 2003, the Socket 939-compatible Athlon 64 chips are eight-generational CPUs that use the AMD64 instruction set, and they are split into three divisions: the regular Athlon 64, the enthusiast-oriented Athlon 64 FX and the Athlon 64 X2. The first two categories are single-core CPUs, which means that they have a single core, or processor unit. The appropriately named Athlon 64 X2, on the other hand, is a dual-core CPU.
The Socket 939 is also compatible with some entries of the low-end Sempron brand, which made its debut in the same year as the socket. The Opteron, which appeared in the following year for server and workstation systems, is the third major AMD processor family that has members compatible with the Socket 939. Each processor uses AMD’s HyperTransport (HT) technology for conducting data transfer, which should be around 800 or 1,000 megahertz (MHz). Additionally, Socket 939 operates within a 0.8-to-1.55-voltage range.