Processor—Interfaces

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Non interleaved

C

 

 

 

 

 

 

 

 

 

 

 

access

C

B

Dual channel interleaved access

BB

B

CH A

CH B

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 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, the IMC operates completely in Dual-Channel Symmetric mode.

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

Intel® Xeon® Processor E3-1200 v3 Product Family

 

Datasheet – Volume 1 of 2

June 2013

20

Order No.: 328907-001