1. Installing Internal Optional Devices
Express5800/R120g-2E User's Guide
73
Chapter 2 Preparations
(2)
Memory LockStep feature (x8 SDDC)
With the Memory LockStep feature, the DIMMs in two groups corresponding to two memory channels (channels
0 and 1, or channels 2 and 3) is multiplexed and operated in parallel to enable x8 SDDC. With this feature, a
single device can detect and correct one to eight-bit error.
Note
•
Memory LockStep feature uses channels 0 and 1 or channels 2 and 3.
•
To use Memory LockStep feature, install N8102-691/692 additional memory card
(two DIMMs of same model).
•
DIMMs used in LockStep set must be of the same model number.
•
Any memory card other than N8102-691/692 additional memory card cannot be
installed together.
The Memory LockStep feature can be used under the following conditions:
•
Install DIMMs in DIMM socket to configure a LockStep set.
•
All the installed DIMMs must be the same capacity.
•
See
Chapter 2 (1. System BIOS)
in "
Maintenance Guide
" to change parameters as shown below.
Advanced
→
Memory Configuration
→
Memory RAS Mode
→
Change to
LockStep
.
•
After restarting, run SETUP again, and check if "
Lock Step
" is displayed for the following parameter.
Advanced
→
Memory Configuration
→
Memory Information
→
CPUx_DIMMx Status
•
Installation order depends on CPU configuration. See the figure below.
Memory controller
Memory controller
LockStep set
#3
LockStep set
#1
LockStep set
#4
LockStep set
#2
LockStep set
#8
LockStep set
#7
LockStep set
#6
LockStep set
#5
