Product guide

IBM Flex System x440 Compute Node 11
The following table shows the maximum memory speeds that are achievable based on the installed
DIMMs and the number of DIMMs per channel. The table also shows the maximum memory capacity at
any speed supported by the DIMM and the maximum memory capacity at the rated DIMM speed.
In the table:
The entries highlighted in red text indicate that the x440 supports higher memory frequencies than the

Intel processor specification. In some instances, this configuration also results larger memory
capacity that the specification recommends.
Cells highlighted with a grey background indicate when the specific combination of DIMM voltage and

number of DIMMs per channel still allows the DIMMs to operate at the rated speed.
Table 4. Maximum memory speeds
DIMM specification UDIMMs RDIMMs LRDIMMs
Ranks Dual-rank DIMMs Single-rank DIMMs Dual-rank DIMMs Quad-rank LRDIMMs
Part numbers 49Y1404
(4 GB)
49Y1406
(4 GB)
49Y1559
(4 GB)
49Y1407 (4 GB)
49Y1397 (8 GB)
49Y1563 (16 GB)
90Y3109 (8 GB)
00D4968 (16 GB)
49Y1567 (16 GB)
90Y3105 (32 GB)
Rated speed 1333 MHz 1333 MHz 1600 MHz 1333 MHz 1600 MHz 1333 MHz
Rated voltage 1.35 V 1.35 V 1.5 V 1.35 V 1.5 V 1.35 V
Max. qty supported* 32 48 48 48 48 48
Max. DIMM capacity 4 GB 4 GB 4 GB 16 GB 16 GB 32 GB
Max. mem. capacity 128 GB 192 GB 192 GB 768 GB 768 GB 1.5 TB
Max memory at
rated speed
128 GB 128 GB 128 GB 512 GB 512 GB 1 TB
Max operating speed (MHz) and operating voltage (operates at rated voltage unless specified)
1 DIMM per channel 1333 MHz 1333 MHz 1600 MHz 1333 MHz 1600 MHz 1333 MHz
2 DIMMs per channel 1333 MHz 1333 MHz 1600 MHz 1333 MHz 1600 MHz 1333 MHz
3 DIMMs per channel No support 1066 MHz 1066 MHz 1066 MHz 1066 MHz 1066 MHz
* The maximum quantity supported is shown for four processors installed. When two processors are installed, the
maximum quantity supported is a half of the quantity that is shown. When one processor is installed, the quantity is
one quarter of that shown.
The following memory protection technologies are supported:
ECC

Chipkill (for x4-based memory DIMMs only; look for "x4" in the DIMM description)

Memory mirroring

Memory rank sparing

If memory mirroring is used, then DIMMs must be installed in pairs (minimum of one pair per processor),
and both DIMMs in a pair must be identical in type and size.
If memory rank sparing is used, then a minimum of one quad-rank DIMM or two single-rank or dual-rank
DIMMs must be installed per populated channel (the DIMMs do not need being identical). In rank sparing
mode, one rank of a DIMM in each populated channel is reserved as spare memory. The size of a rank
varies depending on the DIMMs installed.