MSI 661FM2 User Guide - Page 47

MS-7060 Micro ATX Mainboard DRAM Timing Control This field allows you to select the DRAM timing setting. Setting to [By SPD] enables Max Memclock (Mhz) automatically to be determined by SPD. Selecting [Manual] allows users to configure these fields manually. DRAM CAS Latency When the DRAM Timing Control is set to [Manual], this field is adjustable. The field controls the CAS latency, which determines the timing delay before SDRAM starts a read command after receiving it. Setting options: [2T], [2.5T], [3T]. [2T] increases system performance while [3T] provides more stable system performance. RAS Active Time (tRAS) When the DRAM Timing Control is set to [Manual], this field is adjustable. This setting determines the time RAS takes to read from and write to a memory cell. Setting options: [4T] to [9T]. RAS Precharge Time (tRP) When the DRAM Timing Control is set to [Manual], this field is adjustable. This setting controls the number of cycles for Row Address Strobe (RAS) to be allowed to precharge. If insufficient time is allowed for the RAS to accumulate its charge before DRAM refresh, refreshing may be incomplete and DRAM may fail to retain data. This item applies only when synchronous DRAM is installed in the system. Setting options: [2T] to [5T]. RAS to CAS Delay (tRCD) When the DRAM Timing Control is set to [Manual], this field is adjustable. When DRAM is refreshed, both rows and columns are addressed separately. This setup item allows you to determine the timing of the transition from RAS (row address strobe) to CAS (column address strobe). The less the clock cycles, the faster the DRAM performance. Setting options: [2T] to [5T]. MA 1T/2T Select This setting controls the SDRAM command rate. Selecting Auto allows SDRAM signal controller to run at [1T] (T=clock cycles) rate. Selecting [MA 1T] makes SDRAM signal controller run at [2T] rate. [1T] is faster than [2T]. Setting options: [Auto], [2T], [1T]. 3-12