The buildup to AMD’s launch party for its Ryzen 3000 CPUs, aka third gen Ryzen, aka Zen 2, has been huge. The Ryzen 3000 processors are the first mainstream CPUs to utilize a 7nm manufacturing process. After flirting with the crown for the first two Ryzen generations, this could be the day when AMD claims an outright victory. Will the Ryzen 9 3900X be the best CPU for gaming—and everything else? It’s time to find out.
I’ve already done a deep dive into the Ryzen 3000 and Zen 2 architectural updates. That’s 3,000 words of primer for the interested, so start there if you want to know the nitty gritty details of why things have changed. This is also the final scored review after an initial review in progress—AMD has been working on updated firmware, and I’ve tested and retested the 3900X multiple times. What you see here represents a realistic look at the performance you’ll get.
The focus here will be on the Ryzen 9 3900X, though the 3700X and 3600X are also included in the performance slides. Let’s start with the high-level overview before moving on to the real-world performance results. The short summary of changes for the Zen 2 architecture is still quite extensive.
Zen 2 adds an improved L2 TAGE branch predictor, a larger micro-op cache, doubles the maximum size of the L3 cache (to 32MB per CCX), and doubles the AVX floating point performance. There’s also a third address generation unit (AGU), larger buffers (eg, reorder buffer, integer scheduler, physical register file, entry store queue, and more), multiplication latency is reduced to 3 cycles (from 4), and there are wider buses (256-bit instead of 128-bit) to improve bandwidth. There’s also PCIe Gen4 support, changes to the Infinity Fabric that links everything together, and improvements in memory compatibility.
Wrap all of that up in a 7nm bow, then move the memory controller out of the main CPU chiplet and into a secondary IO chiplet, and stick both into a single package—with the option to have dual CPU chiplets on higher tier models like the 3900X. That’s the Ryzen 3000 family, currently with everything from 6-core/12-thread models like the Ryzen 5 3600 that use a single CPU chiplet with two CCXes, up through the current king of the hill Ryzen 9 3900X with 12-cores and 24-threads spread out over two CPU chiplets—and the Ryzen 9 3950X will be a 16-core/32-thread solution, coming soon. (I hope to have one for testing in the near future.)
Looking at the specs for the new third gen parts compared to the previous generation parts, the main changes are in L3 cache sizes and clockspeeds, as well as pricing. That last bit is especially relevant if we’re looking at street pricing, where the second gen parts are now selling for far less than the original launch prices—the Ryzen 7 2700X costs $240, the 2700 is…