What is Dual Channel Mode?

Is Dual Channel mode something that I need?

"Dual Channel Mode" is a feature that was created to reduce the potential performance bottleneck that exists between the CPU and the Memory Controller. It is enabled when a pair of same-size memory modules are installed into matching banks, usually color coded on the motherboard. Based on our own experience, dual channel mode provides about a 5-10% increase in performance in most games and applications.

Unless specifically required in rare cases, combining memory modules of different sizes in the same machine is compatible and will not affect system stability or reliability in any way.

Most people will not realise any difference if dual channel mode is enabled or not, but if you are looking for absolute best performance, then dual channel mode does provide a slight performance increase.

What is Dual Channel DDR Memory?

There is a common misconception surrounding the term “dual channel DDR”. The same DDR memory modules that can be used in any DDR based system can be used in any dual channel system. Although referred to as “dual channel DDR memory”, it is the systems themselves that are released with either single memory channels or dual memory channels. Dual memory channel designs double the peak bandwidth over equivalent systems that only offer single memory channels. Many of the new systems released as “dual channel” allow the end user to run the system in either single channel OR dual channel memory mode.

Here is an example of how it works: In single channel memory systems, the memory modules are all installed on one channel, with only one access route to the memory controller (the official communicator between the installed memory and the rest of the system).

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In dual channel memory systems, the memory modules are installed on two separate channels, each with its own access route to the memory controller, thus doubling the peak data bandwidth.

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What is Important to Know About Dual Channel DDR Memory Upgrades?

Many dual channel based systems can run in either single channel or dual channel mode. In order to take full advantage of the system running in dual channel mode, the memory modules need to be upgraded in like pairs. If you intend to fully utilize the dual channel features, we recommend purchasing and installing two like memory modules (one for channel A, and one for channel B) now to insure like parts. This should eliminate a potential future headache when deciding to upgrade from single channel to dual channel operation.

A Good Rule of Thumb for Upgrading a Dual Channel DDR Based System

Single Channel Operation: Install one or two modules (mixed or same capacities), but install modules in only one bank.

Dual Channel Operation: Install in like pairs (same speed/capacity*), in first slot of each bank. Second set of modules should also be installed in like pairs (same speed/capacity*) in second slot of each bank. The module pair in the first set of slots does not need to be the same capacity as the module pair in the second set of slots.

* If like speeds or like capacities (or the combination of both) are not installed, the system will automatically revert to single channel operation, regardless of module installation/configuration.

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Additional information about dual channel mode can also be found on wikipedia.