Installing System Components 127• In a dual-processor configuration, the memory configuration for eachprocessor must be identical.• Memory modules of different sizes can be mixed within a memory channel(for example, 2-GB, 8-GB, and 4-GB), but all populated channels musthave identical configurations.• For Optimizer Mode, memory modules are installed in the numeric orderof the sockets beginning with A1 or B1.• For Memory Mirroring or Advanced ECC Mode, the three sockets furthestfrom the processor are unused and memory modules are installedbeginning with socket A2 or B2 and proceeding in the numeric order of theremaining sockets (for example, A2, A3, A5, A6, A8, and A9).• Advanced ECC Mode requires x4 or x8 DRAM device widths.• The memory speed of each channel depends on the memoryconfiguration:– For single or dual-rank memory modules:• One memory module per channel supports up to 1333 MHz.• Two memory modules per channel supports up to 1067 MHz.• Three memory modules per channel are limited to 800 MHz,regardless of memory module speed.– For quad-rank memory modules:• One memory module per channel supports up to 1067 MHz.• Two memory modules per channel are limited to 800 MHz,regardless of memory module speed.• If a quad-rank memory module is installed, then only one other memorymodule can be added to that channel.• If quad-rank memory modules are mixed with single- or dual-rankmodules, the quad-rank modules must be installed in the sockets with thewhite release levers.• If memory modules with different speeds are installed, they will operate atthe speed of the slowest installed memory module(s).
