Opteron is the name of a central processing unit (CPU) family within the AMD64 line. Designed by Advanced Micro Devices (AMD) for the server market, Opteron competed with Intel's Xeon. The Opteron family is succeeded by the Zen-based Epyc, and Ryzen Threadripper and Threadripper Pro series. For Socket 940 and Socket 939 Opterons, each chip has a three-digit model number, in the form Opteron XYY. For Socket F and Socket AM2 Opterons, each chip has a four-digit model number, in the form Opteron XZYY. For all Opterons, the first digit (the X) specifies the number of CPUs on the target machine: