F

Memory

The dc5750 series computers with AMD-based processors come with double data rate 2 synchronous dynamic random access memory (DDR2-SDRAM) dual inline memory modules

(DIMMs).

Ä CAUTION: DDR and DDR2 memory modules are not interchangeable.

DDR2-SDRAM DIMMs

The memory sockets on the system board can be populated with up to four industry-standard

DIMMs. These memory module sockets are populated with at least one preinstalled memory module. To achieve the maximum memory support, you can populate the system board with up to 8GB of memory configured in a high-performing dual channel mode.

For proper system operation, the DDR2-SDRAM DIMMs must be:

■

■ industry-standard 240-pin unbuffered PC2-4300 533 MHz-compliant, PC2-5300 667 MHz-compliant, or PC2-6400

800 MHz-compliant

■ 1.8volt DDR2-SDRAM DIMMs

The DDR2-SDRAM DIMMs must also:

■ support CAS latency 4 (DDR2/533 MHz and DDR2/667 MHz) and CAS latency 5

(DDR2/667 MHz and DDR2/800 MHz)

■ contain the mandatory JEDEC SPD information

In addition, the computer supports:

■

■

■

256Mbit, 512Mbit, AND 1 Gbit non-ECC memory technologies single-sided and double-sided DIMMS

DIMMs constructed with x8 and x16 DDR devices; DIMMs constructed with x4 SDRAM are not supported

✎

The system will not start if you install unsupported DIMMs.

DIMM Sockets

There are four DIMM sockets on the system board, with two sockets per channel. The sockets are labeled XMM1, XMM2, XMM3, and XMM4. Sockets XMM1 and XMM2 operate in memory channel A. Sockets XMM3 and XMM4 operate in memory channel B.

Service Reference Guide, dc5750 437963-001 F–1

Memory

The system board shown may differ from the one in your product.

F–2

Item

1

2

3

4

Description

DIMM socket XMM1, Channel A

DIMM socket XMM2, Channel B

DIMM socket XMM3, Channel A

(populate first)

DIMM socket XMM4, Channel B

(populate second)

Socket Color

White

White

Black

Black

The system will automatically operate in single channel mode, dual channel mode, or flex mode, depending on how the DIMMs are installed.

■ The system will operate in single channel mode if the DIMM sockets are populated in one channel only.

■ The system will operate in a higher-performing dual channel mode if the total memory capacity of the DIMMs in Channel A is equal to the total memory capacity of the DIMMs in

Channel B. The technology and device width can vary between the channels. For example, if

Channel A is populated with two 256MB DIMMs and Channel B is populated with one

512MB DIMM, the system will operate in dual channel mode.

■ The system will operate in flex mode if the total memory capacity of the DIMMs in Channel

A is not equal to the total memory capacity of the DIMMs in Channel B. In flex mode, the channel populated with the least amount of memory describes the total amount of memory assigned to dual channel and the remainder is assigned to single channel. For optimal speed, the channels should be balanced so that the largest amount of memory is spread between the two channels. For example, if you are populating the sockets with one 1GB DIMM, two

512MB DIMMs, and one 256MB DIMM, one channel should be populated with the 1GB

DIMM and one 256MB DIMM and the other channel should be populated with the two

512MB DIMMs. With this configuration, 2 GB will run as dual channel and 256 MB will run as single channel.

■ In any mode, the maximum operational speed is determined by the slowest DIMM in the system.

437963-001 Service Reference Guide, dc5750