AMD RYZEN 7 3700X & RYZEN 9 3900X
The real deal.
The real deal
Back when first generation Ryzen CPUs launched, we lauded their newfound competitiveness, particularly under highly threaded workloads. Power efficiency was also strong, but it lacked that bit of single-threaded performance that kept Intel in the overall lead. 2nd generation Ryzen closed that gap, but only a tiny bit. Now we have 3rd generation Ryzen. It’s just as important for AMD and the market as the first generation was. If the first generation was laying a foundation, then third generation is more like the culmination. Straight up, Ryzen 3 is the real deal and it brings AMD to a level of competitiveness
not seen since the Athlon 64 glory days.
We have to start by drawing attention to just how much of an engineering undertaking Ryzen 3 is. We’d be covering it if there was an architectural change, a process change or a fundamental shift to a chiplet design. Ryzen 3rd gen is all three of those things, with the added challenge of not even changing the socket. There’s also the fact that PCIe 4.0 makes its PC debut. AMD really does deserve credit for accomplishing all that at the same time.
COMPETITION ACROSS THE RANGE
The Ryzen 3rd gen line-up debuts with the launch of the mid to high end models first. The entry level CPUs for now are the 3600 and 3600X hex-core Ryzen 5 models. We’d expect budget quad core versions to follow later in the year. Based on spec alone, our pick of the bunch would be the Ryzen 7 3700X. It’s an 8c/16t part that’s notable for having a healthy 4.4GHz boot clock at a very impressive 65W TDP. The 3800X is a higher clocked eight core model with a 3.9GHz/4.5GHz boost with a 105W TDP.
Topping the range are the Ryzen 9 3900X and 3950X. These models pack 12 and 16 cores into a very respectable 105W TDP. Compare this to the likes of the 16 core Threadripper 2950X at 180W, along with Intel’s 165W Kaby Lake-X models and it’s clear that AMD’s power efficiency has taken a massive step forward. It also means there isn’t a requirement for powerful cooling. The 3900X is on sale now while the 3950X is expected to come on sale in September.
All Ryzen CPUs come with a bundled cooler. Our 3700X and 3900X samples come with the highest spec Wraith Prism RGB model. It’s a capable cooler, though it won’t be able to compete with the larger surface area air coolers or decent AiO’s. It certainly looks good with an attractive splash of RGB lighting.
A MONUMENTAL ENGINEERING FEAT
Ryzen 3rd gen CPUs mark the debut of the Zen 2 architecture. The ‘Matisse’ desktop family we’re covering here will be joined by the ‘Rome’ server CPU family (very exciting for AMD) as well as future Threadripper and likely APUs in the more distant future.
“Topping the range are the Ryzen 9 3900X and 3950X. These models pack 12 and 16 cores into a very respectable 105WTDP. ”
“AM4 has gone from supporting monolithic quad core 28nm CPUs to 7nm multi die sixteen core CPUs plus the shift to PCIe 4.0 while maintaining backwards compatibility. ”
As we mentioned in the intro, the engineering challenge Ryzen 3rd gen represents is enormous. Firstly there’s the move to a chiplet based design. Ryzen 3rd gen CPUs contain three dies, consisting of two core complexes built with the 7nm process, and an I/O die built on 12nm. With that in mind, consider that all AM4 processors must adhere to the same pinout. AM4 has gone from supporting monolithic quad core 28nm CPUs to 7nm multi die sixteen core CPUs plus the shift to PCIe 4.0 while maintaining backwards compatibility. It’s a real feat of engineering. Intel could certainly learn a thing or two from this.
Then there’s the move to 7nm. This allowed AMD to really shrink transistor size and hence the core complexes (CCX). A single CCX is just 74 sq mm, with a big chunk of this being taken up by the L3 cache. These small chiplets means AMD benefits from improved wafer density and lower costs while gaining increased design flexibility and scalability.
Then there’s the architecture itself. Perhaps the biggest architectural gain comes from a redesigned cache hierarchy. A larger micro-op cache, 512k L2 cache and a doubling of the L3 cache to 32Mb per die all add up to a big chunk of the latency improvements between Ryzen 2nd and 3rd generations, which particularly helps to increase game performance.
Additionally there’s an all new TAGE branch predictor, doubled floating point capability, which all put together leads AMD to claim that IPC has been uplifted by up to an impressive 15%, and that’s before taking into account any clock speed improvements.
Additional improvements include higher memory clock support thanks in part to a new memory clock/infinity fabric divider, security vulnerability hardening and on the software side, Windows scheduler improvements with the May 10th 1903 update.
MOVING ONTO THE NUMBERS
So, how do these things perform? The answer: very well! It’s clear that AMD has taken a significant step forward. When comparing
the similarly priced 3900X and 9900K. AMD clearly has the advantage under heavily threaded loads with its 8 vs 12 cores. It also eats almost all of Intel’s single thread lead as well as its gaming advantage. At this point it’s important to note that when the load shifts back to the GPU with higher graphics settings, the difference between all the top performing processors essentially evaporates.
While multithreaded performance is outstanding, AMD hasn’t quite reached performance parity with Intel overall. Lightly threaded performance still matters and if you’re a gamer, Intel has its nose in front there largely thanks to its high clocks, but not necessarily at every price point. If you’re a content creator or someone who can make use of the multithreaded power, then AMD is the best choice right now.
Don’t forget the flagship 3950X. As the highest clocking processor with the most cores, it’s likely that the best is yet to come.
TEMPERATURES AND POWER CONSUMPTION
We used the bundled Wraith Prism RGB which performed surprisingly well. Our 3900X got a bit toasty under sustained all core load but maxed out at 80c which is acceptable. The 3700X fared better and never hit 75c.
Power consumption figures are amazing under load, with both the 3700X and 3900X taking an efficiency lead despite handicap of their extra cores. Idle power was a bit higher than we’d like but we were using beta pre-release BIOS so we’d expect those numbers to improve over time.
COMPELLING. VERY COMPELLING
Zen 2 takes all the things we liked about Zen and Zen+ and makes them better. Multithreaded performance has gone from very good to excellent. Single threaded performance has taken a big jump forwards and AMD’s gaming performance is as competitive as it’s been since the Athlon 64 days.
It’s easy to make the argument that AMD has pulled alongside Intel in outright performance. Consider that the 3900X goes close enough to matching the mighty 9900K in single threaded performance whilst offering more cores and hence significantly better multithreaded performance, all while using less power.
The Ryzen 7 3700X is a wonderful processor. Its power thrifty, runs cool, has mega multithreaded prowess combined with single threaded performance that brings it to within touching distance of Intel’s higher clocked parts. It’s a really good all-rounder.
The 3900X is just as praiseworthy. If you need the multi-threaded grunt then for sure it’s a terrific purchase compared to the likes of AMD’s own Threadripper platform and Intel’s 12 core $1,750 i9 9920X. In that light, the $780 3900X is an absolute steal.
AMD was competitive with Ryzen and Ryzen 2nd gen, but with Ryzen 3rd gen it’s come back to a state of near performance parity. The CPU wars are back in full swing. Intel might hold onto the single threaded and gaming crown, but its lead has shrunk dramatically. Competition is good for everyone. Over to you Intel.
“Power consumption figures are amazing under load, with both the 3700X and 3900X taking an efficiency lead despite handicap of their extra cores. ”