AMD Ryzen 7 5800X3D review: cache money

After taking a closer look at DDR4 versus DDR5, it's now time to return to DDR4 for one last time. Having a much larger cache could mean that the 5800X3D is a little more resistant slower RAM speeds, but is that borne out by our testing?

To find out, we tested the 5800X and 5800X3D in three games with different CPU performance profiles: Ashes of the Singularity, Far Cry 6 and Crysis 3 Remastered. (We've also plotted the Intel 12th-gen results to provide a bit of context, but given that this is DDR5 it's not wholly relevant to today's discussion.)

First up is Ashes of the Singularity Escalation, a great DX12 title that absolutely lives and dies on CPU performance and where fast RAM typically sees noticeable performance improvements. And indeed, the 5800X3D not only provides a noticeable improvement over the 5800X, but we see a larger advantage from the faster RAM on the X3D than the standard 5800X - which goes against our initial hypothesis.

Far Cry 6 is a game that is quite single-threaded, with a lot of processing limited to a single thread, so it's a good test of how faster RAM affects performance in this sort of a more thread-naïve title. Here, the faster RAM makes basically no difference, with a measurable but insignificant improvement in both the 5800X and 5800X3D.

Crysis 3's benchmark turns in very reliable and repeatable performance, making it a good choice for seeing even minor performance variations. Unfortunately, neither processor exhibits beyond a margin-of-error delta with 3600MT/s RAM compared to 3000MT/s.

So while we do see impressive gains from faster RAM in one game, the other two show no difference in performance whatsoever - so our initial hypothesis that the 5800X3D would be more resistant to slow RAM doesn't seem to hold much water. Perhaps that ought to prompt some additional testing at a later date to find out the truth, but we'll leave things here for now.

So what are our final thoughts? Let's wrap it all up on the final page.

AMD Ryzen 7 5800X3D analysis

• Introduction, test rig and content creation benchmarks
• Gaming benchmarks: Flight Simulator 2020, Hitman 3
• Gaming benchmarks: Metro Exodus EE, Black Ops Cold War
• Gaming benchmarks: Cyberpunk 2077, Far Cry 6, Crysis 3 Remastered
• Gaming benchmarks: Memory bandwidth analysis
• AMD Ryzen 7 5800X3D: the Digital Foundry verdict