Asus P5QC User Manual - Page 37

2.4 System memory 2.4.1 Overview The motherboard comes with two Double Data Rate 3 (DDR3) and four Double Data Rate 2 (DDR2) Dual Inline Memory Modules (DIMM) sockets. A DDR3 module has the same physical dimensions as a DDR2/DDR DIMM but is notched differently to prevent installation on a DDR2/DDR DIMM socket, while a DDR3/DDR2 module has a 240-pin footprint compared to the 184-pin DDR DIMM. DDR3 modules are developed for better performance with less power consumption. The figure illustrates the location of the DDR3/DDR2 DIMM sockets: DDR3 module installation Channel Channel A Channel B Sockets DDR3_DIMM_A1 DDR3_DIMM_B1 DDR2 module installation Channel Channel A Channel B Sockets DIMM_A1 and DIMM_A2 DIMM_B1 and DIMM_B2 • You can only install either DDR2 module(s) or DDR3 module(s) on the motherboard; otherwise, the system will not boot up. • DDR2 1066MHz DIMMs work only on the black slots for one DIMM per channel. Ensure to install the DDR2 1066MHz DIMMs ONLY on the BLACK slots! ASUS P5QC 2-11