Asus P5Q PRO - Manual (Page 36)

2-10 Chapter 2: Hardware information
Channel Sockets
Channel A DIMM_A1 and DIMM_A2
Channel B DIMM_B1 and DIMM_B2
2.4 System memory
2.4.1 Overview
The motherboard comes with four Double Data Rate 2 (DDR2) Dual Inline Memory
Modules (DIMM) sockets.
The figure illustrates the location of the DDR2 DIMM sockets: