CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

3.5. Single Channel Versus Dual Channel

When installing memory today, you can install memory modules into a dual-channel configuration versus a single-channel configuration. A single-channel configuration (used for years) mandates a "single lane" used to send and receive information from memory.

With some of today's systems, though, you can install memory in a dual-channel configuration, which allows for two lanes to carry information to and from memory at the same time. This configuration increases overall performance by allowing for more input/output per operation, or clock cycle.

To take advantage of dual-channel memory, you first need to ensure that your motherboard supports dual channel. Dual-channel memory is a function of the memory controller. If your motherboard supports dual-channel memory, you will install the memory modules in pairs. For example, when installing 1GB of RAM, you install two 512MB modules. When you install these modules, install them into the same color slots on the motherboard. If the motherboard does not color-code the memory slots, you install the pair of memory modules in the odd-numbered slots or the even-numbered slots — but not an odd and an even.

NOTE

To leverage-dual channel memory, you must install the same memory modules in pairs. You must use the same type (for example, DDR2 or DDR3) of memory for both modules and the same speed. The two modules must be able to keep up with one another when performing parallel IO.

NOTE

You can purchase dual-channel ...