Gigabyte ga 990x gaming sli socket am3 71 channel atx motherboard specifications cpu am3 socket amd am3 fx processor amd am3 phenomtrade ii processor amd athlontrade ii processor please refer cpu support list for more information hyper transport bus hypertransporttrade 30 5200 mts chipset north bridge amd 990x south bridge amd sb950 memory 4 x ddr3 dimm sockets supporting up to 64 gb of system memory due to a windows 32 bit operating system limitation when