Socket 939 is a PGA socket designed for desktop K8 microprocessors. The socket is primarily used with Athlon 64, Athlon 64 X2 and Athlon FX microprocessors. AMD also manufactured uni-processor single and dual-core Opteron processors for the socket 939, although these processors were just re-branded Athlon 64/64 X2 CPUs with larger level 2 cache. In addition to that small number (compared to the total number of processors for this socket) of socket 939 Sempron processors was produced for this socket.