User`s manual

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1.7 System Memory
1.7.1 Overview
The mainboard comes with two 240-pin DDR2 Dual Inline Memory Modules (DIMM) sockets. You may use 533MHz
(PC2-4200), 667MHz (PC2-5300), or 800MHz (PC2-6400); Non-ECC, Un-buffered 1.8V DDR2 memory modules on
this board (2GB maximum for each slot).
• Some old-version DDR2-800/667 DIMMs may not match Intel®’s On-Die-Termination (ODT)
requirement and will automatically downgrade to run at DDR2-533. If this happens, contact your
memory vendor to check the ODT value.
• Due to chipset limitation, DDR2-800 with CL=4 will be downgraded to run at DDR2-667 by default
setting. If you want to operate with lower latency, adjust the memory timing manually.
• Due to chipset limitation, DDR2-667 with CL=3 will be downgraded to run at DDR2-533 by default
setting. If you want to operate with lower latency, adjust the memory timing manually.
1.7.2 Dual-Channel mode Population Rule
In Dual-Channel mode, the memory modules can transmit and receive data with two data bus lines simultaneously.
Enabling Dual-Channel mode can enhance the system performance. Please refer to the following illustrations for
population rules under Dual-Channel mode.
• In dual-channel configurations, install only identical (the same type and size) DDR2
memory module pairs for each channel. For instance, DIMM_A1 paired with DIMM_B1.
• Always install DIMMs with the same CAS latency. For optimum compatibility, it is
recommended that you obtain memory modules from the same vendor.