An illustration of a memory slot on a computorr mother board

What is Dual-Channel Memory?

Dual-channel RAM is one version of multi-channel memory. All the versions of multi-channel RAM increase data transfer speed by adding more channels of communication between the memory and the memory controller.

How does multi-channel RAM work?

The RAM on the memory module communicates with the rest of the computer through the memory controller on the central processing unit (also known as a CPU or a processor) using a bus.  Some memory controllers have multiple channels for communication with the memory module. This allows faster data exchange, as the data can be sent on more than one channel. There are memory controllers built with one channel, two channels (dual channel), four channels (quad channel), six channels, and eight channels. Six-channel and eight-channel architecture is usually designed for servers.

There are also a few motherboards that run triple-channel architecture. Triple-channel architecture also uses interleaving, which is a method of assigning memory addresses to the memory in a set order.

For dual-channel architecture, the original design combined two 64-bit buses into a single 128-bit bus, which was later called the ganged model. The performance increases were not enough, however. Manufacturers found that two independent buses increased performance more, so the unganged model is usually set by default on most modern processors.

A diagram showing how a memory module communicates with the CPU using both single and dual channels

What other hardware is needed?

To take advantage of multi-channel memory, the processor must have a memory controller that supports the multi-channel architecture and the motherboard must support the architecture. In addition, the RAM modules must be matched in as groups that correspond with the level of multi-channel architecture, for example, dual channel requires pairs, quad channel requires four modules, and so on. Motherboards that support multi-channel architecture will frequently have color-coded memory slots to help ensure that matched modules are inserted. Most DRAM manufacturers will sell memory in "kits" to ensure that the memory modules match in capacity, speed, latency, number of chips and sides, and the size of rows and columns. It's best to buy RAM in kits compatible with your motherboard and processor if you intend to take advantage of multi-channel memory. If memory modules that do not match are inserted, they will usually work, but at the specifications of the slowest module. 

For the best results, use the Crucial® Advisor™ tool or System Scanner tool to find compatible kits for your motherboard. Read here about how to install memory

Conclusion

If you're looking to significantly speed up your computer, multi-channel architecture can do it. But there is a significant investment in compatible hardware to support the speed.


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