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AMD Ryzen 9 5900X review

With its 12 cores, the 5900X offers impressive multi-threaded performance but modest clock speeds and a somewhat high price dent its broader appeal.

AMD Ryzen 9 5900X review

Our Verdict


Despite a massive price cut, Intel’s cutthroat approach with its Core i7-12700K ultimately has this once proud 12-core CPU beaten.

It wasn’t that long ago that the Ryzen 9 5900X price was £600, but this 12-core Zen 3 CPU has seen a monumental price cut recently. That’s all thanks to the likes of Intel’s Core i7-12700K and Core i9-12900K retailing for well south of the AMD CPU’s launch price, and offering compelling performance for the cash.

With 12 cores and 24 threads, this is still a mighty CPU, of course, even if it’s based on the now-aging Zen 3 architecture. However, while it was once one of the most powerful gaming CPUs and multi-threaded monsters in one potent chip, there are plenty of new kids on the block looking to usurp the Ryzen 9 5900X for both gaming and more multi-threaded workloads.

With two core complex dies (CCDs), the CPU has much the same setup as the 16-core Ryzen 9 5950X, and it still has access to the full 64MB L3 cache these dies offer, despite having four of its cores disabled. That figure still pales compared to the 96MB on offer with the Ryzen 7 5800X3D courtesy of its 3D V-Cache, but there are also some seriously high frequencies on offer with the 5900X, with single cores able to hit 4.8GHz, and all 12 cores can sit at 4.1GHz when they’re churning through multi-threaded workloads.

We managed to overclock it to 4.6GHz across all 12 of its cores too, with a vcore of 1.25V, bringing a 500MHz benefit to all-core multi-threaded loads, but you’ll lose 200MHz of peak boost speed for lightly-threaded software if you do this. As a result, depending on your priorities, it might be better to spend some time playing with AMD’s Precision Boost Overdrive 2 instead of going for an all-core overclock, unless you’re gunning for maximum multi-threaded performance.

In terms of performance, the Ryzen 9 5900X was the second fastest AMD CPU on test in our RealBench image editing test, which stresses single-threaded performance, although it was pipped to the post by the Core i5-12600K. The Core i7-12700K was faster still, bettering the AMD CPU in our heavily multi-threaded Handbrake video encoding test and in Cinebench, although not by huge margins, and the 5900X clawed back some ground when it was overclocked too.

Our gaming tests saw the 5900X offer a much slower average frame rate than the Intel CPU in Far Cry 6, but a slightly higher 99th percentile result., Meanwhile, in Watch Dogs: Legion the 5900X was soundly beaten and didn’t really offer a significant improvement in power consumption either, with our 5900X test system only drawing 20W less under load than our Core i7-12700K test setup.

AMD Ryzen 9 5900X pros and cons


  • Decent multi-threaded performance
  • Compatible with first-gen AM4 motherboards
  • Manual overclock benefits multi-threaded speed


  • Cheaper CPUs are faster
  • Ryzen 7 5800X3D is much faster in games
  • Manual overclock cuts lightly-threaded performance

AMD Ryzen 9 5900X specs

The Ryzen 9 5900X specs list is:

Base frequency 3.7GHz
Max boost frequency 4.8GHz
Core Zen 3
Manufacturing process 7nm
Number of cores 12 x physical (24 threads)
IGP None
Simultaneous Multithreading (SMT) Yes
Cache 64MB L3 cache, 6MB L2 cache
Memory controller Dual-channel DDR4, up to 3200MHz
Packaging AMD Socket AM4
Thermal design power (TDP) 105W
Features Precision Boost 2, Precision Boost Overdrive, FMA3, F16C, SHA, BMI / BMI1 + BMI2, AVX2, AVX, AES, SSE4a, SSE4, SSSE3, SSE3, SSE2, SSE

AMD Ryzen 9 5900X price

Current pricing for the 5900X is much more competitive than at launch but its slightly underwhelming clock speeds mean several other CPUs hit a better balance of performance for similar money.

Price: Expect to pay $490 / £350

AMD Ryzen 9 5900X review conclusion

Despite a massive price cut, the Ryzen 9 5900X isn’t able to topple the cheaper Core i7-12700K, which is faster in most tests and sometimes noticeably so. Of course, buying a new Intel CPU will involve buying a new motherboard too, so the 5900X is still worth considering if you own an older Ryzen CPU and fancy an upgrade. Ultimately, however, the Intel CPU is a better buy, and if you’re only interested in gaming performance and don’t mind sticking with socket AM4 for a while, the Ryzen 7 5800X can offer higher frame rates

For more CPU options, check out our guide to the best gaming CPU, which details a range of different CPUs to suit different needs and budgets.