Core i7 12700K and Core i5 12400F: memory bandwidth analysis

We'll take a closer look at DDR4 versus DDR5 next time on Digital Foundry, but for now let's examine how different DDR5 speeds affect gaming performance. We've tested the two most common options, DDR5-5200 and DDR4-4800, with kits provided by Crucial and Corsair, while also doing a bit of cheeky overclocking to reach 5400MT/s and 5600MT/s in a few games.

First up is Ashes of the Singularity, a great DX12 title that absolutely lives and dies on CPU performance, where fast RAM typically sees noticeable performance improvements. The 12700K sees a three percent performance advantage from switching from 4800MT/s to 5200MT/s RAM, a little more than we observed from other 12th-gen parts. For the 12400F, the advantage is around two percent for the faster RAM, so again measurable but not particularly impactful.

Far Cry 6 next. We again see a small two to three percent difference in performance here between 4800MT/s and 5200MT/s for both of our new CPUs, with a jump up to 5400MT/s netting a further one percent increase. Given the frame-rates already on offer, RAM speed doesn't seem to make much of a difference here - at least with the kits we have on hand.

Crysis 3's benchmark turns in very reliable and repeatable performance, making it a good choice for seeing even minor performance variations. With faster RAM, the 12700K gains just one percent performance between 4800MT/s and 5400MT/s, while the 12400F gains two percent over the same progression. It's again not impactful at all, so our advice remains to just get the cheapest DDR5 you can - at least until higher frequency and/or lower latency kits are available.

That was a bit of a damp squib, so let's move onto our final verdict for the 12400F and 12700K.

Intel Core i7 12700K and Core i5 12400F analysis

• Introduction, test rig and content creation benchmarks
• Gaming benchmarks: Flight Simulator 2020, Hitman 3
• Gaming benchmarks: CS:GO, Metro Exodus EE, Black Ops Cold War
• Gaming benchmarks: Cyberpunk 2077, Far Cry 6, Crysis 3 Remastered
• Gaming benchmarks: Memory bandwidth analysis [This Page]
• Intel Core i7 12700K and Core i5 12400F: the Digital Foundry verdict