Why is it important to pick dual channel memory when putting together a PC or laptop?

Introduction

Dual channel memory is a configuration in which two or more memory modules (DIMM or SO-DIMM) are installed in a computer system and operate together as a single memory subsystem. This configuration can provide a number of benefits, including increased performance, especially when it comes to gaming and other latency-sensitive applications.

Gaming performance

Performance gains are especially noticeable on laptops using NVIDIA Optimus (MSHybrid), because with NVIDIA Optimus the iGPU (integrated graphics unit in the CPU) is responsible for screen output and receives the images from the dGPU through system memory in what's called the "Optimus Copy Engine". Dual channel memory boosts the performance of such a setup by providing more speed, bandwidth, and lower latency, thus avoiding the system memory becoming a bottleneck for gaming performance.

iGPU performance

Aside from NVIDIA Optimus, dual channel memory can also boost the iGPU's own performance, because the iGPU uses system memory as video memory, and video memory is especially sensitive to speed, bandwidth, and latency. This is relevant for any scenario in which the iGPU is used for light gaming or content creation workloads.

DDR4 vs. DDR5

These advantages are true for both DDR4 and DDR5 system memory. Although a single DDR5 SO-DIMM module now has two memory channels whereas DDR4 only had one, those channels only have a bus width of 32-bit each, whereas DDR4's single channel bus width was 64-bit. Thus, adding the second DDR5 module still boosts performance of memory-sensitive applications by increasing memory channel bandwidth and turning the system essentially into a "quad channel" configuration.

How to order dual channel memory on bestware

On bestware, XMG's partnered shop platform, you can spot the dual channel configurations by looking out for the "2 x" in front of the memory capacity. This indicates that two memory modules are being used. The total combined capacity of those two modules is written in brackets. See this screenshot for reference:

Price differences between dual and single channel configuration may vary with system memory prices. Usually they are at least around the same ballpark when comparing single and dual channel configurations with the same total capacity. In this example screenshot (dated January 2023), the dual channel configuration is even less expensive than the single channel configuration of the same total capacity.

How to check if my system already has dual channel memory

The fastest way to check if your system is using dual channel is to open the Task Manager (Ctrl+Shift+Esc) and check the Memory performance tab. In the bottom right corner, you see how many of your RAM slots are being used.

• 1 of 2 = Single channel
• 2 of 2 = Dual channel

How to upgrade a system from single to dual channel memory

If you have initially configured your system with single channel memory, you can upgrade it to dual channel by adding a second RAM module of the same model number. This is done in two ways:

• Read your current RAM module's model number with software such as CPU-Z or HWiNFO64. Alternatively, you can also use the following command in Windows Command Prompt (cmd.exe): "wmic memorychip get devicelocator, partnumber". Then find exactly the same module in any retail shop of your choice.
• Contact our support team. We will be able to check our system to see which memory module was originally installed in your PC or laptop and we will make you an offer for a second module if we still have this particular model number in stock.

When upgrading from single to dual channel memory, it is important to really use two modules of the same model number. Different modules may have identical clock speed and latencies, but may have different sub-timings and a different "Rank x Org" configuration, leading to performance bottlenecks that will prevent you from gaining the full potential of your dual channel configuration. That's why we strongly recommend to use two identical modules which have exactly the same model number.

For more information on how to upgrade RAM modules in your laptop, please see this FAQ article:

• Disassembly for SSD and RAM upgrades