IBM 71413SU - System x3950 M2 Reference

Contents

26 IBM System x3950 M2 and x3850 M2 Technical IntroductionFigure 13 Memory hardware on the x3850 M2 and x3950 M2Mirroring takes place across two memory cards. The memory DIMMs in card 1 are mirroredto the memory DIMMs in card 2. The memory DIMMs in card 3 are mirrored to the memoryDIMMs in card 4. Therefore, with memory mirroring enabled in the BIOS, you can hot-swapany memory card as long as the hot-swap enabled LED is lit. Refer to x3850 M2 and x3950M2 User’s Guide for complete instructions about how to hot-swap a memory card.After memory mirroring is enabled, the data that is written to memory will be stored in twolocations. For read operations, data is read from the DIMMs with the least amount of reportedmemory errors through memory scrubbing.Table 10 shows the possible BIOS settings for the initialization scrub control. The setting isaccessed by going to Advanced Setup → Memory Settings → Initialization ScrubControl.Table 10 Initialization Scrub ControlDIMM 1DIMM 2DIMM 3DIMM 4DIMM 5DIMM 6DIMM 7DIMM 8Memory hot-swap enabled LEDMemory-card/DIMM error LEDMemory-card power LEDLight path diagnostics buttonVisible from topof memory cardMemory card 1Memory card 2Memory card socket 3Memory card socket 4Setting FunctionScrub on Every Boot Performs full memory test on every bootScrub only after ACCyclePerforms scrub only after AC has been removed or appliedDisabled Relies on standard memory test and run time scrub engine to ensurememory is “good”