Acer Altos R920 Series, User Manual

Page: 189 / 206

171
Memory configuration
The BIOS configures the system memory into the best possible
configuration after comparing the current FBDIMM population with
the desired memory configuration selected by the user in System BIOS.
Possible configurations are:
• Dual-channel mode (Maximum performance mode)
• Single-channel mode
• Memory sparing mode
• Memory mirroring mode
Only one memory mode can be selected at a time and the BIOS
defaults to maximum performance mode. Support is also included for
memory sparing, where a portion of each memory board is reserved
for failover.
Dual-channel mode
Dual-channel mode (maximum performance mode) is the default
memory configuration and provides the highest system performance
and increased FBD bandwidth. This requires each lock-stepped pair of
FBDIMMs on a branch to be identical. A lock-stepped FBDIMM pair is
defined as the FBDIMMs installed in identically numbered FBDIMM
sockets on both memory boards (channels) on a given memory branch.
No RAS (reliability, availability, and serviceability) features are enabled
in this configuration.
To configure memory to maximum performance mode:
1 Run BIOS setup. See “Entering BIOS setup” on page 100.
2 Use the up and down arrow keys to select the Advanced menu.
3 Use the up and down arrow keys to select Memory
Configuration , then press Enter . The Memory Configuration
menu appears.
4 Use the up and down arrow keys to select Memory RAS and
Performance Configuration , then press Enter . The Memory RAS
and Performance Configuration menu appears.
5 Set the Select Memory RAS Configuration to RAS Disabled.
6 Press F10 to save changes and exit.