Rules For Populating Memory Slots; Intel ® Flex Memory Technology Operation - Intel BX80623I32100 Datasheet

®
Figure 2-1. Intel Flex Memory Technology Operation
2.1.3.2.1 Dual-Channel Symmetric Mode
Dual-Channel Symmetric mode, also known as interleaved mode, provides maximum
performance on real world applications. Addresses are ping-ponged between the
channels after each cache line (64-byte boundary). If there are two requests, and the
second request is to an address on the opposite channel from the first, that request can
be sent before data from the first request has returned. If two consecutive cache lines
are requested, both may be retrieved simultaneously since they are ensured to be on
opposite channels. Use Dual-Channel Symmetric mode when both Channel A and
Channel B DIMM connectors are populated in any order, with the total amount of
memory in each channel being the same.
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.
Note: The DRAM device technology and width may vary from one channel to the other.
2.1.4

Rules for Populating Memory Slots

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. The usage of DIMM modules with different latencies is allowed,
but in that case, the worst latency (per channel) will be used. For dual-channel modes,
both channels must have a DIMM connector populated and for single-channel mode,
only a single-channel may have one or both DIMM connectors populated.
Note: In a 2 DIMM Per Channel (2DPC) daisy chain layout memory configuration, the furthest
DIMM from the processor of any given channel must always be populated first.
22
C
B B
C H A C H B
B – T h e la rg e s t p h y s ic a l m e m o ry a m o u n t o f th e s m a lle r s iz e m e m o ry m o d u le
C – T h e re m a in in g p h y s ic a l m e m o ry a m o u n t o f th e la rg e r s iz e m e m o ry m o d u le
T O M
N o n in t e r le a v e d
C
a c c e s s
B
D u a l c h a n n e l
in te r le a v e d a c c e s s
B
Interfaces
Datasheet, Volume 1