MSI K7D MASTER User Guide - Page 24

DDR 1 DDR 2 DDR 3 DDR 4 Hardware Setup Memory Installation The mainboard provides 4 sockets for 184-pin, 2.5V DDR DIMM with 8 memory banks. To operate properly, at least one DIMM module must be installed. DDR DIMM Slots (DDR 1~4) You can install PC1600/PC2100 DDR SDRAM modules on the DDR DIMM slots (DDR 1~4). DDR (Double Data Rate) SDRAM is similar to conventional SDRAM, but doubles the rate by transfering data twice per cycle. It transfers data on both the rising and falling edges of the clock. Conventional SDRAM only uses the rising edge of the clock to transfer data. Therefore, conventional SDRAM is called SDR (Single Data Rate) SDRAM. DDR SDRAM uses 2.5 volts as opposed to 3.3 volts used in SDR SDRAM, and requires 184-pin DIMM modules rather than 168-pin DIMM modules used by SDR SDRAM. DDR SDRAM is also known as SDRAM-II, DDR DRAM and DSDRAM (Double-Speed DRAM). Two types of DDR are available at the time of writing: PC1600 & PC2100. PC1600 DDR SDRAM running at 100MHz will produce about 1.6GB/s memory bandwidth. PC2100 running at 133MHz will produce 2.1GB/s memory bandwidth. High memory bandwidth makes DDR an ideal solution for high performance PC, workstations and servers. Note: Registered DIMMs can be placed into DDR1~4 but unbuffered DIMMs can be placed into DDR1~2 only. 2-7