Intel Xeon Wolfdale E3210 P4X-UPE3210-316-6M1333 Data Sheet

Datasheet

269

The system memory controller supports DDR2 protocol with two independent 64 bit 

wide channels each accessing one or two DIMMs. It supports a maximum of two un-

buffered ECC or non-ECC DDR2 DIMMs per channel thus allowing up to four device 

ranks per channel.

The system memory controller supports two memory organization modes, Single 

Channel and Dual Channel.

In this mode, all memory cycles are directed to a single channel.

Single channel mode is used when either Channel A or Channel B DIMMs are populated 

in any order, but not both.

This mode provides maximum performance on real 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 guaranteed to be on opposite channels. 
Dual channel symmetric mode is used when both Channel A and Channel B DIMMs are 

populated in any order with the total amount of memory in each channel being the 

same, but the DRAM device technology and width may vary from one channel to the 

other. 

 is a sample dual channel symmetric memory configuration showing the rank 

organization.

In this addressing mode the lowest DRAM memory is mapped to dual channel operation 

and the top most DRAM memory is mapped to single channel operation. In this mode 

the system can run at one zone of dual channel mode and one zone of single channel 

mode simultaneously across the whole memory array.

This mode is used when Intel

®

 Flex Memory Mode is enabled and both Channel A and 

Channel B DIMMs are populated in any order with the total amount of memory in each 

channel being different. 

Rank 3

0 MB

2560 MB

0 MB

2560 MB

Rank 2

256 MB

2560 MB

256 MB

2560 MB

Rank 1

512 MB

2048 MB

512 MB

2048 MB

Rank 0

512 MB

1024 MB

512 MB

1024 MB