Intel BX80646I74770, CM8064601466200 manual System Memory Organization Modes, Single-Channel Mode

Interfaces—Processor

Note: System memory timing support is based on availability and is subject to change.

2.1.3System Memory Organization Modes

The Integrated Memory Controller (IMC) supports two memory organization modes – single-channel and dual-channel. Depending upon how the DIMM Modules are populated in each memory channel, a number of different configurations can exist.

Single-Channel Mode

In this mode, all memory cycles are directed to a single-channel. Single-channel mode is used when either Channel A or Channel B DIMM connectors are populated in any order, but not both.

Dual-Channel Mode – Intel® Flex Memory Technology Mode

The IMC supports Intel Flex Memory Technology Mode. Memory is divided into symmetric and asymmetric zones. The symmetric zone starts at the lowest address in each channel and is contiguous until the asymmetric zone begins or until the top address of the channel with the smaller capacity is reached. In this mode, the system runs with one zone of dual-channel mode and one zone of single-channel mode, simultaneously, across the whole memory array.

Note: Channels A and B can be mapped for physical channel 0 and 1 respectively or vice versa; however, channel A size must be greater or equal to channel B size.

Figure 2. Intel® Flex Memory Technology Operations

TOM

C

B

CH A

B

CH B

C

B

B

Non interleaved access

Dual channel interleaved access

CH A and CH B can be configured to be physical channels 0 or 1

B – The largest physical memory amount of the smaller size memory module

C – The remaining physical memory amount of the larger size memory module

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

Desktop 4th Generation Intel® Core™ Processor Family, Desktop Intel® Pentium® Processor Family, and Desktop Intel® Celeron® Processor Family

December 2013	Datasheet – Volume 1 of 2
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