Intel G870 CM8062307260115 User Manual

22

Datasheet, Volume 1

When both channels are populated with the same memory capacity and the boundary 
between the dual channel zone and the single channel zone is the top of memory, IMC 
operates completely in Dual-Channel Symmetric mode. 

The DRAM device technology and width may vary from one channel to the other. 

This mode trades performance for system design flexibility. Unlike the previous mode, 
addresses start at the bottom of Channel A and stay there until the end of the highest 
rank in Channel A, and then addresses continue from the bottom of Channel B to the 
top. Real world applications are unlikely to make requests that alternate between 
addresses that sit on opposite channels with this memory organization, so in most 
cases, bandwidth is limited to a single channel.

This mode is used when Intel Flex Memory Technology is disabled and both Channel A 
and Channel B DIMM connectors are populated in any order with the total amount of 
memory in each channel being different. 

In all modes, the frequency of system memory is the lowest frequency of all memory 
modules placed in the system, as determined through the SPD registers on the 
memory modules. The system memory controller supports one or two DIMM 
connectors per channel. For dual-channel modes both channels must have at least one 
DIMM connector populated and for single-channel mode only a single-channel may 
have one or both DIMM connectors populated. 

DIMM0 must always be populated within any memory configuration. DIMM0 is the 

furthest DIMM within a channel and is identified by the CS#[1:0], ODT[1:0], and 

CKE[1:0] signals.

CH. B

CH. A

CH. B

CH. A

CH. B

CH. A

CL

0

Top of 
Memory

CL

0

CH. B

CH. A

CH.A-top
DRB

Top of 
Memory