Recently, we published an article, “Does dual-channel memory make difference in gaming performance?”, where we concluded that, in a gaming computer with an independent video card, using dual-channel memory mode has little or no influence in gaming performance. But, what about CPU integrated video performance? Will the conclusion be the same? That’s what we will check today.
To understand the theory under the dual-channel architecture and how to enable it, please read our tutorial “Everything you need to know about the Dual-, Triple-, and Quad-Channel Memory Architectures”.
Buy what is the impact of the dual-channel technology in a system that uses the integrated GPU? When you use an independent video card, the video memory, where the textures and other data related to the 3D video are stored, is located at the video card and is independent from the main RAM. The speed of this memory depends only on the video card characteristics. As the performance of a game usually depends mostly on the video card performance, in this case using a faster main RAM makes little difference, since it is not used to store video data.
However, when you use the integrated video, the GPU (“Graphics Processing Unit”) is located on the processor and uses the main computer RAM as video memory. So, it gets benefit from the higher bandwidth (due to the dual-channel technology or to higher memory clock). Besides that, we must remember that this bandwidth is shared between the GPU and the CPU, which, in theory, raises the need for a high memory bandwidth.
We can easily check how using dual-channel memory affects the GPU bandwidth using GPU-Z on an A8-7670K (which we tested recently) with two DDR3-2133 memory modules, first installed in single-channel, and then in dual-channel. Check Figures 1 and 2. In single-channel, the integrated video uses a 64-bit bus, with a bandwidth of 17.1 GiB/s, while with dual-channel, the bus is 128-bit wide and the bandwidth doubles.
Figure 1: video memory bandwidth in single-channel
Figure 2: video memory bandwidth in dual-channel
In order to measure the impact of installing the memory in dual-channel over the gaming framerate, we used two different hardware configurations. In the next page, you will see the configurations we used in this test.