We’ve already tested the impact of dual-channel memory and memory speeds in general in the case of the Ryzen 3000 processors. These chips use an MCM design, whereas the Renoir mobile APUs are monolithic in nature (just one CCD). So you’ll probably be wondering whether the impact of dual-channel RAM is as significant as the case of the desktop Zen 2 lineup. Let’s have a look:
TechEpiphany tested the Ryzen 9 4900HS in both single-channel and dual-channel mode and found the result to be rather significant. The benchmark was conducted using Capcom’s Open World title, Monster Hunter. For the majority of the benchmark, the dual-channel is at least 50% faster than single-channel. At times, the delta even swells up to twice that figure and even higher. Notable examples include 1:47 and 0:49. Basically, the conclusion here is that you NEED dual-channel memory with the Renoir parts too.
Before buying confirm that the device has two memory DIMMs, and if not, make sure you add the second one. For a nominal price, you’ll be getting a healthy performance upgrade.
AMD Ryzen 4000 APUs: 2666MHz vs 3200MHz Gaming Performance
Once again, 3200MHz proves to be a major step up from the standard 2666MHz DDR4 RAM. The delta stays mostly in the 10 FPS range which is quite significant, to be honest. Once again, we recommend that you opt for a Renoir laptop packing 3200MHz memory. Most ASUS offerings come with 3200MHz RAM out of the box, so we suggest looking at those.

AMD Ryzen 4000 “Renoir” Mobile APUs Architectural Overview: Yes, it’s Monolithic
As we know, the Renoir parts are monolithic, so why does memory still have such a big impact on gaming performance? This is because CPU and iGPU are still connected by the Infinity Fabric which runs at 3600MT/s. Therefore, running the IF closer to this figure significantly cuts down the CPU-GPU latency, thereby improving performance.