My PC is a mix of older and newer parts, and Unreal Engine 5 games often push my CPU to nearly 100% regardless of the graphics settings. Games seem to run much better when global illumination is disabled, so I'm wondering whether my DDR4-2400 memory is limiting the CPU's ability to handle map processing and Lumen's ray-traced lighting.
Would upgrading to the fastest memory my motherboard supports—DDR4-3200—make a meaningful difference, or is DDR4 simply too slow for UE5 and Lumen? Could the real limitation be elsewhere?
My main components are an ASRock B350 motherboard, Ryzen 5 5600X, RTX 5060 Ti 16GB, and 32GB of DDR4-2400. The motherboard and memory originally came from a 2017 build, while the CPU was upgraded from a Ryzen 7 1700X last year.
4 Answers
I run a Ryzen 5 5600X with 32GB of DDR4-3200, and UE5 games are generally playable; the graphics card makes a much bigger difference with Lumen enabled. Faster memory can help a little, but it won’t compensate for a CPU that is already fully loaded. Make sure your current kit is running with XMP or DOCP enabled, since it may be stuck at its default speed.
The CPU is more likely the main limitation than memory bandwidth. A six-core Ryzen 5000 processor can struggle in demanding UE5 games, especially with hardware Lumen enabled. A Ryzen 7 5800X3D would be a much more noticeable upgrade and should still work with relatively slow DDR4, assuming your motherboard BIOS supports it.
DDR4-3200 should be fine for gaming. Moving from 2400 to 3200 may provide a small improvement, but it probably won’t transform UE5 performance. Benchmarks generally show only a modest difference between DDR4-3200 and 3600, so I’d prioritize a CPU upgrade or GPU settings before spending much on memory.
DDR4-2400 is definitely old for Ryzen, but it isn’t likely to be solely responsible for the severe slowdown you’re seeing. Since your existing kit dates back to the original 2017 system, a 32GB DDR4-3200 or 3600 kit could be a reasonably inexpensive improvement. Just keep expectations realistic: the 5800X3D would likely have a larger impact, and you should check whether the B350 board has the required BIOS support.
The memory and motherboard are both from 2017, and I’ve never enabled XMP or tried a faster kit. I may compare the cost of new DDR4 with moving to a 5800X3D, since the latter could be a better upgrade.