ECS A790GXM-AD3 motherboard comes with two x16 PCI Express 2.0 slots, two PCI Express x1 slots and two standard PCI slots. When only one video card is used, the main PCI Express x16 slot really works at x16, but when two video cards are installed both slots work at x8.

So A790GXM-AD3 provides a great flexibility in terms of video configuration. You can use its on-board video, you can disable the on-board video and install up to two video cards and you can also enable the on-board video to work in parallel with a video card under CrossFire mode if you install a card that is compatible with Hybrid Graphics technology (read our SLI vs. CrossFire tutorial for a complete list of compatible cards).

A standard peripheral power plug is available next to the main PCI Express x16 slot to provide extra power to the graphics card. ECS doesn’t say exactly when we should use this connector, so it is better if you always keep it installed to the power supply.

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Figure 2: Slots.

Socket AM3 CPUs support both DDR2 and DDR3 memories, but the kind of memory you can have depends on the kind of motherboard they are installed on, socket AM2+ or socket AM3, respectively. Being a socket AM3 motherboard, ECS A790GXM-AD3 supports only DDR3 memories. It comes with four memory sockets and in order to achieve the maximum performance possible you need to install two or four memory modules in order to enable the dual channel feature, which doubles the available memory bandwidth. If two modules are used, you need to install them on sockets with the same color. On this motherboard sockets one and two are orange and sockets three and four are yellow.

The maximum amount of memory you can have is 32 GB (by using four 8 GB modules), up to DDR3-1333/PC3-10600.

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Figure 3: Memory sockets.