Core i9 12900K and Core i5 12600K: memory bandwidth analysis

We'll take a closer look at DDR4 versus DDR5 in the future - as our DDR4 board hasn't arrived yet - but for now, let's take a look at 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. We've also dipped our toes into the murky waters of DDR5 and 12900K overclocking, with a few quick-and-dirty tweaks to wring out a modicum of extra performance.

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. We see a five percent improvement going from DDR5-4800 to DDR-5200 on the 12900K and four percent on the 12600K, a measurable but not particularly exciting increase for this game. Overclocking to 5400MT/s or 5600MT/s doesn't result in any noticeable performance improvement, despite multiple retests, with all runs within the margin of error.

Far Cry 6 next. We get a paltry two percent difference in performance here between DDR5-4800 and DDR5-5200, while overclocking the CPU provides a further two percent increase. Altogether, it's not really worth it for a game that already runs quite well at 1080p.

Crysis 3 always served as an example of a game that didn't really get faster with better RAM, and that looks to be true in the remaster as well. Having RAM set to 4800MT/s provides more or less identical performance to 5200MT/s; perhaps we'd start to see a small advantage through more serious overclocking.

Ultimately, there's not a massive performance gap between the two RAM kits we have on hand - DDR5-5200 CL38 and DDR5-4800 - so going for the cheaper option probably makes sense for most people. This is especially true as early DDR5 modules like these should pale in comparison with later versions, if the transition from DDR3 to DDR4 was anything to go by.

Intel Core i9 12900K and Core i5 12600K analysis

• Introduction, hardware breakdown, test system
• 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 i9 12900K and Core i5 12600K: the Digital Foundry verdict