Two bits
Does fast RAM provide a real advantage?
If you’re looking into building a new system, of course you’ll need some RAM. The DDR4 standard is now well and truly mature and speeds are faster than ever. While the base speed for DDR4 is 2133MHz, that speed is obsolete. Even 2400 and 2666MHz kits aren’t much cheaper than a now commonplace 3200MHz kit. That means 3200MHz is effectively the current baseline, and there’s an argument that 3600MHz is becoming the sweet spot in 2020. We won’t focus on timings here other than to say that lower timings are advantageous, though comparing the performance of something like DDR4-3200 C14 to DDR4-3600 C16 is highly application-specific.
So, is it worth going for RAM at 4000MHz or even higher? Unless you’re a competitive overclocker, the answer is no. Intel CPUs tend not to benefit a whole lot from very fast RAM. Part of this is due to the inherent lower latency of their single die designs. This is thought to be the reason for Intel’s strong gaming performance vs AMD. Also, if you’re planning a B460 build, you’ll be limited to a maximum of 2666MHz or 2933MHz if you use an i7 or i9 CPU. On Z series chipsets, 4000MHz and faster can introduce compatibility issues, where XMP may not work without some additional tweaking.
If you’re building a system with a higher-end Ryzen 3000 series processor, then you’ll strongly want to consider a 3600MHz kit. This is because the memory clock on these systems is tied to the Infinity Fabric clock, which is the interconnect that AMD uses for cross-die communication. The Infinity Fabric tops out at 1800MHz or a bit higher. Bearing in mind that DDR means Double Data Rate, this makes 3600MHz RAM run 1:1 with the Infinity Fabric. AMD systems can run a lot higher than 3600MHz RAM, but running the Infinity Fabric slower than the RAM clock incurs a latency penalty, which cannot be overcome unless you are running very high speed RAM. Grab yourself a good 3600MHz kit for your AMD system. Set it and forget it. Also note that faster RAM benefits the graphics performance of AMD’s APUs. You wouldn’t want to go overboard with expensive RAM on such a system, but if you’re gaming on a 3200G or 3400G, an extra $20 or so spent on a faster RAM kit will deliver higher FPS.
Very fast kits above 4000MHz still carry a fairly hefty price premium which makes their price/ performance highly questionable. Additionally, if you’re running high resolutions and graphics settings, you really won’t see much benefit with very fast RAM. You might get a bit of a boost with higher minimums, but that’s about it. Where you’ll see more of a benefit is with lower graphics settings or games that you play at very high FPS. Even then it depends on the game itself.
In summary, a good 3200MHz or 3600MHz kit is sufficient for most use cases. Faster memory can be beneficial in some applications, so a bit of research into the apps you commonly use could prove to be an eye opener. Your apps or game may surprisingly love the extra bandwidth.
“So, is it worth going for RAM at 4000MHz or even higher? Unless you’re a competitive overclocker, the answer is no.”