IBM 81Y6843 manual Memory options,  Ecc

Memory options

IBM DDR3 memory is compatibility tested and tuned for optimal System x performance and throughput. IBM memory specifications are integrated into the light path diagnostics for immediate system performance feedback and optimum system uptime. From a service and support standpoint, IBM memory automatically assumes the IBM system warranty, and IBM provides service and support worldwide.

The IBM System x3650 M3 supports up to nine DDR3 DIMMs when one processor is installed and up to 18 DIMMs when two processors are installed. However, the maximum number of DIMMs is limited by the number of ranks in the DIMMs:

RDIMMs

Up to 18 single-rank RDIMMs (nine per processor) for a maximum of 72 GB (18x 4 GB)

Up to 18 dual-rank RDIMMs for a maximum of 288 GB (18x 16 GB)

Up to 12 quad-rank RDIMMs for a maximum of 192 GB (12x 16 GB)

UDIMMs

Up to 12 dual-rank UDIMMs for a maximum of 48 GB (12x 4 GB)

Each processor has three memory channels, and there are three DIMMs per channel. RDIMMs can be populated three per channel. However, UDIMMs can only be populated two DIMMs per channel. That is, you can have up to 18 RDIMMs installed in the server, but only up to 12 UDIMMs. Mixing UDIMMs and RDIMMs is not supported.

Maximum memory speed is limited by memory speed supported by the specific processor and by the number and type of DIMMs installed (whichever has a lower memory speed rating), as follows:

Intel Xeon 5600 series processors:

1333 MHz when one or two single-rank or dual-rank RDIMMs per channel are installed or one UDIMM per channel is installed

1066 MHz when one quad-rank RDIMM per channel is installed or two UDIMMs per channel are installed

800 MHz when three single-rank or dual-rank RDIMMs or two quad-rank RDIMMs per channel are installed

The server supports both 1.5 V and 1.35 V DIMMs. Mixing 1.5 V and 1.35 V DIMMs in the same server is supported for Intel Xeon 5600 series processor-based systems, in such a case all DIMMs operate at 1.5 V. Intel Xeon 5500 series processor-based systems do not support 1.35 V DIMMs.

The following memory protection technologies are supported:

ECC

ChipKill (for x4-based RDIMMs)

Memory mirroring

Memory sparing

If memory mirroring is used then DIMMs must be installed in pairs (minimum of one pair per each CPU), and both DIMMs in a pair must be identical in type and size. If Memory Sparing is used then DIMMs must be installed in sets of three, and all DIMMs in the same set must be identical in type and size. Memory sparing is only supported for Intel Xeon 5600 series processor-based systems.

The following table lists memory options available for x3650 M3 server.

IBM System x3650 M3 14