Gigabyte 990FXA-UD3 Motherboard

Memory Support

AMD CPUs have an embedded memory controller, meaning that it is the processor, not the chipset, that defines what memory technologies you can have and the maximum amount of memory that is possible. The motherboard, however, may have a limitation as to how much memory can be installed.

The integrated memory controller from socket AM3+ processors supports DDR3 memories up to 1,600 MHz.  According to Gigabyte, the 990FXA-UD3 supports memories up to 1,866 MHz.

The Gigabyte 990FXA-UD3 has four memory sockets. According to Gigabyte, this motherboard supports up to 32 GiB if you use four 8 GiB modules.

In order to enable the dual-channel mode, you must install two or four memory modules. On the Gigabyte 990FXA-UD3, all memory sockets are black. When installing two memory modules, you will have to skip one socket, i.e., you must install one module in the first socket and the other module in the third socket (and not in the second one).

Figure 3: Memory sockets; install two or four modules for the best performance