1. Installing Internal Optional Devices
Express5800/B120f User's Guide
52
Chapter 2 Preparations
(2)
Memory Lock Step Feature (x8 SDDC)
In Memory Lock Step feature, the DIMMs in two groups defined between two memory channels (channels 2 and
3) is multiplexed and operated in parallel to enable x8 SDDC (x8 Single Device Data Correction). With this
feature, a single device can detect and correct one to eight-bit error.
Note
•
Memory LockStep feature uses channels 2 and 3.
•
DIMMs used in LockStep set must be of the same model number.
Memory Lock Step feature can be used under the following conditions:
•
Install two DIMMs in DIMM socket to configure a Lock Step set.
•
Both of DIMMs to be used for LockStep set should be of the same model number.
•
See
Chapter 2 (1. System BIOS)
in "
Maintenance Guide
", run SETUP, change parameters as shown below,
save the settings, and exit from SETUP.
Advanced
→
Memory Configuration
→
Memory RAS Mode
→
Change to
LockStep
.
•
After restart, run SETUP again, and check if "
Lock Step
" is displayed for the following parameter.
Advanced
→
Memory Configuration
→
Memory Information
→
CPUx_DIMMx Status
CH2
CPU1
Memory Controller
CPU1-DIMM4
CH3
CH1
CPU1-DIMM1
CPU1-DIMM2
CPU1-DIMM3
CPU1-DIMM5
CPU1-DIMM6
CH2
CPU2
1
Memory Controller
CPU2-DIMM4
CH3
CH1
CPU2-DIMM1
CPU2-DIMM2
CPU2-DIMM3
CPU2-DIMM5
CPU2-DIMM6
LockStep set #3
LockStep set #1
LockStep set #4
LockStep set #2
