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AMD Ryzen 9 3900X review

AMD goes in for the kill. Here's a preview of the new 3rd-gen Ryzen chips sitting, as they do, between the Core i5-9600K and Core i7-9700K.

Mockup of PC CPU as Imperial Battlecruiser in opening scene to Star Wars

AMD’s first-gen Ryzen CPUs brought some welcome competition back to the CPU market, where Intel had been idly knocking out mildly tweaked quad-core mainstream CPUs year after year. However, Ryzen was clearly lacking in a few areas, some of which were addressed by Zen+, but it’s with Zen 2 that AMD is moving in for the kill.

It brings more boosting algorithm tweaks, a move to 7nm transistors, a transition to a chiplet design, as well as increased core counts, all for much less money than the equivalent Intel CPUs.

The Ryzen 7 3700X retails for £320 inc VAT, sitting between the Core i5-9600K and Core i7-9700K, which are Intel’s overclockable six and eight-core CPUs. However, neither of these Intel CPUs support Hyper-Threading, while all of AMD’s 3rd Gen Ryzen CPUs announced so far offer the company’s equivalent – Simultaneous Multithreading (SMT), so the Ryzen 7 3700X and Ryzen 9 3900X sport 16 and 24 threads respectively.

Clock speed boosting is also more aggressive. You just need to run the latest May 2019 Windows update and install the new Ryzen drivers – there’s no manual tweaking or other software needed. The memory controller has been improved too, with 3600MHz memory now readily supported, running in sync with the CPU’s Infinity Fabric.

Both CPUs also offer higher boost frequencies than any Zen+ CPU, with the Ryzen 7 3700X hitting a maximum of 4.4GHz, while we observed an all-core boost of 4GHz in multi-threaded workloads. The Ryzen 9 3900X, meanwhile, has a 4.6GHz maximum boost frequency, while we spotted an all-core boost of up to 4.05GHz.


There’s a full exploration of Zen 2 performance coming soon, but it’s safe to say that the Ryzen 9 3900X blew us away. For starters, its single-threaded image editing score of 67,140 was the fastest of any CPU we’ve tested, and this test is usually a safe haven for Intel. Thanks to its 12 cores, it was also massively quicker than the Core i9-9900K in our heavily multi-threaded Handbrake video encoding benchmark

With its additional four cores and eight threads over the Core i9-9900K, the new Ryzen also clocked up an extra 200,000 points in the video encoding test – its system score of 306,884 made a mockery of the Intel CPU’s 243,615. AMD has made massive gains in games too, with the Ryzen 7 3700X adding 13fps to the Ryzen 7 2700X’s minimum of 90fps in Far Cry 5.