Hardware Reference Guide

Upgrading system memory
The computer comes with double data rate 4 synchronous dynamic random access memory (DDR4-SDRAM)
dual inline memory modules (DIMMs).
The memory sockets on the system board are populated with at least one preinstalled memory module. To
achieve the maximum memory support, you can populate the system board with up to 64 GB of memory
congured in a high-performing dual-channel mode.
For proper system operation, the DIMMs must adhere to the following specications:
● Industry-standard 288 pin
● Unbuered non-ECC PC4-19200 DDR4-2400 MHz compliant
● 1.2 volt DDR4-SDRAM memory modules
● CAS latency 17 DDR4 2400 MHz (17-17-17 timing)
● Mandatory JEDEC SPD information
The computer supports the following:
● 512 MB, 1 GB, 2 GB, and 4 GB non-ECC memory technologies
● Single-sided and double-sided memory modules
● Memory modules constructed with ×8 and ×16 DDR devices; memory modules constructed with ×4
SDRAM are not supported
NOTE: The system does not operate properly if you install unsupported memory modules.
Installing a memory module
There are four memory sockets on the system board, with two sockets per channel. The sockets are labeled
DIMM1, DIMM2, DIMM3, and DIMM4. Sockets DIMM1 and DIMM3 operate in memory channel B. Sockets DIMM2
and DIMM4 operate in memory channel A.
The system will automatically operate in single-channel mode, dual-channel mode, or ex mode, depending
on how the DIMMs are installed.
NOTE: Single-channel and unbalanced dual-channel memory congurations will result in inferior graphics
performance.
● The system operates in single-channel mode if the DIMM sockets are populated in one channel only.
● The system operates 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 1 GB
DIMMs and Channel B is populated with one 2 GB DIMM, the system operates in dual-channel mode.
● The system operates in ex 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 ex 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. If one channel will have more memory than the
other, the larger amount to Channel A. For example, if you populate the sockets with one 2 GB DIMM and
three 1 GB DIMMs, Channel A should be populated with the 2 GB DIMM and one 1 GB DIMM, and Channel B
Upgrading system memory 13