Data Sheet

Interfaces
24 Datasheet, Volume 1 of 2
Dual-Channel Symmetric Mode (Interleaved 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 System Memory Frequency
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 up to two DIMM connectors
per channel. If DIMMs with different latency are populated across the channels, the
BIOS will use the slower of the two latencies for both channels. For Dual-Channel
modes both channels should have a DIMM connector populated. For Single-Channel
mode, only a single channel can have a DIMM connector populated.
Figure 2-1. Intel
®
Flex Memory Technology Operations