IBM Flex System x440 Compute Node, Инструкция по установке и обслуживанию

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There are three memory modes:
v
Independent-channel mode:
Independent-channel mode provides a maximum
of 384 GB of usable memory per processor and 1536 GB of usable memory with
all four processors installed using 32 GB DIMMs. DIMMs must be first installed
in the last physical DIMM connector of each channel. DIMMs should also be
installed one DIMM per channel first. The best performance is seen with an even
memory distribution among all four channels on the microprocessor. DIMMs can
be installed without matching sizes. Individual channels may run at different
DIMM timings, but all channels must run at the same interface frequency.
DIMMs with different timing parameters can be installed in different connectors
of the same channel, but only timings that support the slowest DIMM are
applied to all the DIMMs. Faster DIMMs operate at timings that are supported
by the slowest installed DIMM.
v
Mirrored-channel mode:
In mirrored-channel mode, memory is installed in
pairs. Both DIMMs in a pair must be identical in capacity, type, and rank count.
The channels are grouped in pairs with each channel receiving the same data.
One channel is used as a backup of the other, which provides redundancy. In
mirrored-channel mode, memory must be installed in pairs. The memory content
is mirrored between channel 0 and channel 1 and between channel 2 and
channel 3. Mirrored-channel mode requires that channel 0 and channel 1, and
channel 2 and channel 3 are be populated identically in regard to size and
organization. DIMM connector populations within a channel do not have to be
identical, but the same DIMM connector location across channel 0 and channel 1
and across channel 2 and channel 3 must be populated in the same way. The
effective memory that is available to the system is only half of what is installed.
v
Rank-sparing mode:
In rank-sparing mode, one memory DIMM rank serves as a
spare of the other ranks on the same channel. The spare rank is held in reserve
and is not used as active memory. The spare rank must have identical or larger
memory capacity than all the other active DIMM ranks on the same channel.
After an error threshold is surpassed, the contents of that rank are copied to the
spare rank. The failed rank of DIMMs is taken offline, and the spare rank is put
online and used as active memory in place of the failed rank.
The following notes describe additional information that you must consider
when you select rank-sparing memory mode:
– Memory sparing on one channel is independent of the sparing on all other
channels.
– You can use the Setup utility to determine the status of the DIMM ranks.
– If only one DIMM is present in a channel and the DIMM is dual or single
rank, then sparing mode should not be enabled.
Rank-sparing on one channel is independent of the sparing on all other
channels. You can use the Setup utility to determine the status of the DIMM
ranks.
Install DIMMs in the order that is indicated in the following table for
independent-channel mode.
Table 12. DIMM population sequence for independent-channel mode
Number of DIMMs
installed 1 microprocessor
installed 2 microprocessors
installed 4 microprocessors
installed
1 DIMM 4 DIMM 4 DIMM 4
2 DIMMs 1 and 4 DIMMs 4 and 16 DIMMs 4 and 16
3 DIMMs 1, 4, and 9 DIMMs 1, 4, and 16 DIMMs 4, 16, and 33
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IBM Flex System x440 Compute Node Types 7917 and 2584: Installation and Service Guide