Datasheet

Cisco UCS B420 M3 Blade Server
CONFIGURING the SERVER
13
— When mixing different densities of 1600-MHz RDIMMs within a channel, memory will
run at 1.5 V (performance mode) only.
— You cannot mix RDIMMs with LRDIMMs
— DIMMs default to performance mode (1.5 V). To run DIMMs in power-savings mode
(1.35 V), change the server BIOS settings.
■ To optimize memory performance:
— Configure DIMMs identically for each CPU
— Fill banks equally across the CPU. See DIMM population guidelines in Table 24,
Table 25, and Table 26 on page 39.
—Populate less than 3 DPC
— Select DIMMs with the highest clock speed for a given processor
■ For systems implementing 3-DPC with E5-4600 series processor family CPUs:
— Maximum memory speed for 1600-MHz DIMMs is 1333 MHz when using 16 GB DIMMs
with E5-4650, E5-4640, or E5-4617 CPUs. Maximum memory speed for all other
configurations is 1066 MHz.
— Memory always runs at 1.5 V regardless if the BIOS setting is low-power mode
(1.35 V) or performance mode (1.5 V)
■ For systems shipping wit E5-4600 v2 series processor family CPUs, DIMM speeds are as shown
in
Table 5.
Table 5 DIMM Speeds for Systems Shipping with E5-4600 v2 Series CPUs
For Systems Shipping with E5-4600 v2 Series CPUs
DIMM
speeds
DPC
1333 Capable v2 CPU 1600 Capable v2 CPU 1866 Capable v2 CPU
LRDIMM RDIMM LRDIMM RDIMM LRDIMM RDIMM
1.35V 1.5V 1.35V 1.5V 1.35V 1.5V 1.35V 1.5V 1.35V 1.5V 1.35V 1.5V
1600
DIMM
1DPC 1333 1333 1333 1333 1600 1600 1333 1600 1600 1600 1333 1600
2DPC 1333 1333 1333 1333 1600 1600 1333 1600 1600 1600 1333 1600
3DPC 1066 1066 NA 1066 1066 1066 NA 16 GB -
1333
1066 1066 NA 16 GB -
1333
8 GB -
1066
8 GB -
1066