The attack of the 12-core! The Ryzen 3000 series has already impressed us, and now it is the turn of the 3900X to show us what it is capable of. We pit the Ryzen 9 against the Intel Core i9-9900K to see which can claim the gaming desktop CPU crown. Read on to find out which has the edge and which delivers the better overall package.
AMD is on the right track to make life difficult for Intel with the continuous improvement of its Ryzen Zen series. The company is now on its third Zen generation in as many years, which should be good news for the consumer, as it challenges Intel to remain competitive too.
The Ryzen 3000 series is the first to bring 7 nm chips to the desktop market, although AMD had already introduced 7 nm manufacturing to its Radeon VII and Navi GPUs. However, the Ryzen 3000 series is not entirely 7 nm, with AMD using a 12 nm process for their I/O dies. These also include the memory controller, which AMD has separated from the CPU die underneath the heat spreader. The latter is housed under so-called CCD clusters, which TSMC manufactures.
The Ryzen 9 3900X consists of two CCD clusters, each with two CCX modules. Each CCX core integrates three CPU cores, yielding 12 cores overall. The Ryzen 9 3900X supports simultaneous multithreading (SMT) too, allowing it to execute up to 24 threads simultaneously. The CPU has 70 MB of combined L2 and L3 cache, now referred to as game cache, which is a massive improvement over the Ryzen 2000 series. AMD took a similar step with Zen+ over Zen too.
It is worth keeping in mind that there is still more to come from Zen 2, with AMD releasing the Ryzen 9 3950X in September. This will have 16 cores, which should offer even better multicore performance than the Ryzen 9 3900X.
AMD recommends using DDR4-3733 CL17 RAM with Zen 2 processors. DDR4-3600 CL16 offers better value for money, but DDR4-3733 CL17 allows Infinity Fabric (IF) to run synchronously with the RAM, resulting in the lowest possible latency speeds. However, as the graph to the right illustrates, using higher-clocked RAM forces IF to run in 2:1 mode, rather than 1:1 as it does with 3733 C17, which increases latency speeds.
Thankfully, the Zen 2 architecture does not require buying a new motherboard. AMD and its partners are publishing BIOS updates for all X470 and B450 chipsets, making them compatible with the Ryzen 3000 series. Even X370 and B350 boards are partially supported too, although we would recommend checking whether your motherboard will work with Zen 2 before buying a new CPU.
Unfortunately, full PCIe 4.0 is currently limited to the new X570 chipset. While some OEMs offer PCIe 4.0 support for older motherboards, AMD has prevented this with the current set of AGESA codes.
AMD Ryzen processors at a glance
Model
Cores/Threads
Base clock
Turbo clock
L3 cache
TDP
Launch price
Ryzen 9 3900X
12/24
3.8 GHz
4.6 GHz
64 MB
105 W
€529 (~US$590)
Ryzen 7 3800X
8/16
3.9 GHz
4.5 GHz
32 MB
105 W
€429 (~US$480)
Ryzen 7 3700X
8/16
3.6 GHz
4.4 GHz
32 MB
65 W
€349 (~US$390)
Ryzen 5 3600X
6/12
3.8 GHz
4.4 GHz
32 MB
95 W
€265 (~US$297)
Ryzen 5 3600
6/12
3.6 GHz
4.2 GHz
32 MB
65 W
€209 (~US$234)
Ryzen 7 2700X
8/16
3.7 GHz
4.3 GHz
16 MB
105 W
€319 (~US$357)
Ryzen 7 2700
8/16
3.2 GHz
4.1 GHz
16 MB
65 W
€289 (~US$323)
Ryzen 5 2600X
6/12
3.6 GHz
4.2 GHz
16 MB
95 W
€225 (~US$252)
Ryzen 5 2600
6/12
3.4 GHz
3.9 GHz
16 MB
65 W
€195 (~US$218)
Ryzen 7 1800X
8/16
3.6 GHz
3.7 GHz
16 MB
95 W
€559 (~US$626)
Ryzen 7 1700X
8/16
3.4 GHz
3.5 GHz
16 MB
95 W
€439 (~US$491)
Ryzen 5 1600X
6/12
3.6 GHz
4.0 GHz
16 MB
95 W
€280 (~US$313)
We used the following hardware for our test system:
AMD Ryzen 9 3900X
MSI MEG X570 Godlike (BIOS 1.20, Default Settings, XMP 1 for DDR4-3600 CL16)
Antec 1,200 W power supply
G-Skill Trident Z Royal Gold DDR4 3600 2 x 8 GB kit. Set to DDR4 3600 CL16-16-16-36
Corsair MP600 2 TB M.2 PCIe 4.0 SSD
Intel Optane 905 480 GB SSD
AMD Radeon RX 5700 XT
AMD Radeon RX Vega 64
Raijintek PEAN Benchtable
AMD kindly supplied us with the CPUs, motherboard, RAM and SSDs for this system. Additionally, Caseking generously created an NBC-customised Raijintek case that we have featured in previous CPU reviews.
Processor Benchmarks
The Ryzen 9 3900X completed our CPU benchmarks with flying colours, often outperforming the Core i9-9900K by a clear margin. However, our review unit could not do so in every discipline, with AMD still falling short of Intel in single-core tasks. Zen 2 has improved massively over Zen+, but the Ryzen 9 3900X scored around 2% less than the Core i9-9900K in Cinebench R15 Single 64Bit, for example. By contrast, the Ryzen 9 3900X outscored the Ryzen 7 2700X and Threadripper 2920X by 19% and 17%, respectively. Above all, these differences underline the improved performance that additional cores and the switch to 7 nm brings.
Recent AMD processors have had better multicore performance than their Intel counterparts, so it is unsurprising to see the Ryzen 9 3900X continue this trend. Our review unit scored a colossal 49% more than the Core i9-9900K in CB R15 Multi 64Bit, while it achieved a healthy 16% lead over the Threadripper 2920X too. Incidentally, the latter also has 12 cores and can execute up to 24 threads, underlining the improvements that AMD has made between generations.
Most games currently lack the optimisation for utilising more than 8 cores, which means that the Ryzen 9 3900X cannot make use of its full potential. The same goes for synthetic gaming benchmarks, with the Ryzen 9 3900X often scoring less than the Ryzen 7 3700X in 3DMark, for example. The difference between the two CPUs is often only around 2% though, which is negligible. The Ryzen 9 3900X also has a 6% lower performance rating than the Core i9-9900K, but again, this is not a massive difference. Incidentally, the Core i7-8700K achieves the highest performance rating of the CPUs in our comparison table, despite not being the best gaming CPU that money can buy.
The same is true in most of the games that we tested at 720p, although the Ryzen 9 3900X occasionally achieves a few frames more than the Ryzen 7 3700X. Forza Horizon 4 and For Honor are good examples of the Ryzen 9 3900X having an advantage over its lesser Zen 2 sibling, but the latter enjoys a 2% advantage in other games like The Witcher 3. By contrast, the Core i9-9900K consistently scores more than the Ryzen 9 3900X in our gaming benchmarks, despite AMD having narrowed that gap by up to 25% compared to the Ryzen 7 2700X.
The gaps between the best AMD and Intel CPUs narrow further at higher resolutions, although mainly in the games that are not CPU heavy. Generally, the Core i9-9900K enjoys a 4% advantage over the Ryzen 7 3700X and Ryzen 9 3900X at 1080p and beyond. The two Zen 2 processors are on par with each other though.
We used the Radeon RX Vega 64 for our first set of benchmarks for the sake of comparability, but we also thought it was apt to see what performance improvements PCIe 4 brings. Hence, we re-ran our gaming benchmarks with the Radeon RX 5700 XT, which offers around 10% higher frame rates than the Radeon RX Vega 64. However, the same applies to the Ryzen 7 2700X, so the added bandwidth that PCIe 4.0 offers appears to deliver no tangible benefit when gaming. Regardless, you can still expect a performance bump if you switch from the Radeon RX Vega 64 to the Radeon RX 5700 XT.
Our test system worked smoothly and without issue during our tests. We noticed no long waiting times either, which should come as no surprise from a 12-core powered system. We also had a fast SSD on hand, so we decided to see whether PCIe 4.0 offered any improved transfer speeds over PCIe 3.0. The 2 TB Corsair SSD that we used is a quick drive even when running on the latter, but PCIe 4.0 helped it achieve around 68 MB/s 4K read speeds, which is exceptionally fast. This should help the system load small files quickly, which will reduce OS and in-game loading times.
We doubt that most people would notice the difference between PCIe 3.0 and PCIe 4.0 in daily use though. The latter will significantly improve sequential read and write speeds thanks to its doubled bandwidth, but the results feel negligible in practice.
The Ryzen 9 3900X hovers around the Ryzen 7 3700X in PCMark, which suggests that the benchmark cannot utilise the former’s 12 cores. Nevertheless, the Ryzen 9 3900X still performed well, with it outscoring the Core i9-9900K in PCMark 10 and managing practically the same as the Core i7-9700K in PCMark 8.
AMD processors now, like those developed by Intel, exceed their stated thermal design power (TDP). The Ryzen 9 3900X has a 105 W TDP, although it can exceed this as we found out with our Ryzen 7 3700X review unit. Derestricting the TDP in the BIOS allows the Ryzen 9 3900X to hit 142 W, which is significantly higher than its specified TDP.
Our test system consumed 81.6 W at idle, which is just ahead of the Ryzen 7 3700X on 79.2 W. Power consumption increased to 229 W while running CB R15 Multi 64Bit, which is only 5% higher than what the Ryzen 7 2700X managed in the same test. A fairer comparison would be with the Threadripper 2970WX, as it also has 12 cores and supports 24 threads. The Threadripper 2970WX, by comparison, peaked at 273 W during the same test, underlining the efficiency of the Zen 2 architecture.
Power consumption averaged 210 W during a Prime95 stress test but peaked at 256 W, although this value excludes how much our test monitor was drawing from the mains. The CPU cannot always maintain its peak TDP, which explains why our test system averaged significantly lower than its peak consumption.
We also looked at power consumption while gaming, with the Ryzen 9 3900X proving more economical than the Ryzen 7 2700X. Our Ryzen 9 3900X-powered test system consumed 392 W while gaming, which is only 4% more than the Ryzen 7 3700X did. Most of that power goes on the RX Vega 64 though.
The included Wraith Prism cooler struggled to keep the Ryzen 9 3900X cool during our tests, with core temperatures peaking at 86 °C during our stress test in an open test setup. Temperatures will rise in a closed case, so we would recommend using at least a better quality air cooler. Socket AM4 air coolers currently cost around US$65, but we would suggest using a 240 or 280 AIO if possible.
We also tried overclocking the Ryzen 9 3900X, but with limited success. We managed to briefly achieve 4.3 GHz on all cores, but core temperatures quickly reached 100 °C in CB R15 Multi 64Bit even with the CPU fan set to 100% and in an open test system. Power consumption averaged 321 W during CB R15 Multi 64Bit with the CPU running at 4.3 GHz too, which is an increase of almost 100 W. In short, this is too much additional wattage for the Wraith Prism cooler to dissipate.
AMD claims that the Ryzen 9 3900X can reach 4.6 GHz, but this is only with its internal overclocking (PBO) features disabled, which hobbles single-core performance. In short, we would not recommend overclocking the Ryzen 9 3900X unless you have an AIO cooler. Even then, the performance gains do not justify the enormous increase in power consumption or the worse single-core performance.
Pros
+consistently good system performance
+excellent gaming performance
+12 cores and 24 threads
+energy efficient
+future-proofed
+PCI Express 4.0
+stylish stock cooler
+still using Socket AM4
+soldered heat spreader
Cons
-unreliable TDP specification
-relatively expensive X570 platform
-comparatively expensive at launch by AMD standards
-PCIe 4.0 only with the X570 chipset
-stock cooler gets loud under load
-high core temperatures with the stock cooler
-hardly any overclocking potential
Verdict
AMD has put a lot of pressure on Intel with the release of the Ryzen 3000 family. The company has got a lot right too, while the reinvigorated competition in the desktop CPU market should be music to people’s ears. However, owners of a current Intel platform need not worry, as the Core i9-9900K remains better suited for gaming than the Ryzen 9 3900X. If you use your PC exclusively for gaming, then Intel remains the better choice.
The steady improvements are now paying off, with AMD having significantly improved the single-core performance of its desktop processors. The Ryzen 9 3900X almost hits the heights of the Core i9-9900K in single-core tasks and pulls clear in multi-core work. Games are still the forte of the Core i9-9900K though.
However, we would recommend considering the Ryzen 9 3900X if you are a streamer or content creator, as the processor shines in multi-core work. Better still, it somehow has comparably low power consumption for a 12-core chip. AMD has also mostly eliminated the single-core performance deficit that existed between Intel processors and the Ryzen 2000 series, with the Ryzen 9 3900X coming close to the Core i9-9900K. Currently, games do not benefit from more than 8 cores, but that could change in the future, which would place the Ryzen 9 3900X in a good position.
The Ryzen 9 3900X retails for US$590, although availability is currently scarce. Hence, the processor may be closer to the Core i9-9900K at launch, but prices should eventually drop down, which would make the Ryzen 9 3900X better value for money than Intel’s current flagship desktop processor.
A somewhat bitter aftertaste remains though as only the X570 chipset can take advantage of PCIe 4.0. At least X470 and B450 boards will support the new Matisse processors after a BIOS update. Even the older X370 and B350 boards are partially compatible too, which is a bonus. We would recommend checking whether your board will work in advance of buying a Ryzen 3000 chip though.
Ultimately, the PCIe 4.0 restrictions should not be a deal breaker for most people as it currently offers little practical advantage in games over PCIe 3.0 despite its higher bandwidth.
Overall, the Ryzen 9 3900X is currently the best consumer desktop CPU on the market thanks to its excellent multi-core performance. The Core i9-9900K has the edge over AMD’s 12-core Zen 2 chip, but we would only recommend choosing the former over the latter if you are an FPS junkie. If not, go with the Ryzen as it offers a better all-round experience than the Core i9.
I was already interested in technology from an early age, and I was able to study for my dream job as an IT Systems Electronics Engineer. Subsequently, I started 12 years of military service, during which I learned a lot about technology and constantly kept my knowledge up to date with the latest developments. As I like to share my knowledge, I found Notebookcheck was a very good opportunity for this. In addition, I also work a lot with water cooling and network security.
Translator:Alex Alderson - Senior Tech Writer - 9677 articles published on Notebookcheck since 2018
Prior to writing and translating for Notebookcheck, I worked for various companies including Apple and Neowin. I have a BA in International History and Politics from the University of Leeds, which I have since converted to a Law Degree. Happy to chat on Twitter or Notebookchat.