Asus P7H55/USB3 - Manual (Page 20)

1-8 Chapter 1: Product introduction
1.4 System memory
1.4.1 Overview
The motherboard comes with four Double Data Rate 3 (DDR3) Dual Inline Memory Modules
(DIMM) sockets.
A DDR3 module has the same physical dimensions as a DDR2 DIMM but is notched
differently to prevent installation on a DDR2 DIMM socket. DDR3 modules are developed for
better performance with less power consumption.
The figure illustrates the location of the DDR3 DIMM sockets:
Recommended memory configurations
One DIMM:
Install one memory module in slot A1 or B1 first as a single-channel operation.
Two DIMMs (dual-channel operation):
Four DIMMs (dual-channel operation):