Asus RS120-E4 User Guide - Page 25

2.3 System memory 2.3.1 DIMM sockets location The system motherboard comes with four Double Data Rate II (DDR2) Dual Inline Memory Modules (DIMM) sockets to support 240-pin DDR2 modules. The figure illustrates the location of the DDR2 DIMM sockets: ® P5M2-R 128 Pins 112 Pins DIMM_A2 DIMM_A1 DIMM_B2 DIMM_B1 P5M2-R.240-pin.DDR2.DIMM.sockets 2.3.2 Memory configurations You may install 256 MB, 512 MB, 1 GB, and 2 GB unbuffered ECC or non‑ECC DDR2-533/667 DIMMs to the DIMM sockets. • Always install DIMMs with the same CAS latency. For optimum compatibility, it is recommended that you obtain memory modules from the same vendor. Visit the ASUS website for an updated DDR2 Qualified Vendors List for this motherboard. • Due to chipset resource allocation, and depending on the number of expansion cards installed, the following conditions may occur: - the system may detect less than 8 GB system memory when you installed four 2 GB DDR2 memory modules - may show an available memory space of less than 4 GB when you installed four 1 GB DDR2 memory modules • Three DDR2 DIMMs installed into any three memory sockets will function in Dual channel asymmetric mode. • When installing a single or two DIMMs, install the modules on the blue slots (DIMM_A1/DIMM_B1). Refer to the recommended memory configuration table below. Recommended memory configurations Mode Single channel mode Dual channel mode Number of memories 1 1 2 4 DIMM socket DIMM_A1 V V V DIMM_A2 V DIMM_B1 V V V DIMM_B2 V Dual channel (asymmetric mode) 3 V V V ASUS RS120-E4/PA4 2-