Asus H81M-CS User Guide - Page 15

1.4 System memory 1.4.1 Overview This motherboard comes with two Double Data Rate 3 (DDR3) Dual Inline Memory Module (DIMM) sockets. A DDR3 module is notched differently from a DDR or DDR2 module. DO NOT install a DDR or DDR2 memory module to the DDR3 slot. According to Intel® CPU spec, DIMM voltage below 1.65V is recommended to protect the CPU. DIMM_A1 DIMM_B1 Channel Channel A Channel B Sockets DIMM_A1 DIMM_B1 H81M-CS H81M-CS 240-pin DDR3 DIMM sockets 1.4.2 Memory configurations You may install 1GB, 2GB, 4GB, and 8GB unbuffered non‑ECC DDR3 DIMMs into the DIMM sockets. • You may install varying memory sizes in Channel A and Channel B. The system maps the total size of the lower-sized channel for the dual-channel configuration. Any excess memory from the higher-sized channel is then mapped for single-channel operation. • Due to Intel® chipset limitations, DDR3 1600MHz and higher memory modules on XMP mode will run at the maximum transfer rate of DDR3 1600MHz. • Always install DIMMs with the same CAS latency. For optimal compatibility, we recommend that you install memory modules of the same version or date code (D/C) from the same vendor. Check with the retailer to get the correct memory modules. • Due to the memory address limitation on 32-bit Windows® OS, when you install 4GB or more memory on the motherboard, the actual usable memory for the OS can be about 3GB or less. For effective use of memory, we recommend that you do any of the following: - Use a maximum of 3GB system memory if you are using a 32-bit Windows® OS. - Install a 64-bit Windows® OS if you want to install 4GB or more on the motherboard. - For more details, refer to the Microsoft® support site at http://support.microsoft. com/kb/929605/en-us. • This motherboard does not support DIMMs made up of 512 megabits (Mb) chips or less. • Memory modules with memory frequency higher than 2133 MHz and its corresponding timing or the loaded X.M.P. Profile is not the JEDEC memory standard. The stability and compatibility of these memory modules depend on the CPU's capabilities and other installed devices. • The maximum 16GB memory capacity can be supported with 8GB or above DIMMs. ASUS will update the memory QVL once the DIMMs are available in the market. ASUS H81M-CS 1-7