AMD Ryzen 9 5900X review

The AMD Ryzen 9 5900X is one of the best CPUs for high-end gaming around

AMD Ryzen 9 5900X
Best in Class
The AMD Ryzen 9 5900X is one of the best gaming processors you're going to find anywhere.
(Image: © Future)

TechRadar Verdict

The AMD Ryzen 9 5900X is an absolute monster of a CPU, bringing the biggest gen-on-gen jump in single-core performance in years, which helps make the processor stronger across the board. The best part? You don't even need a new motherboard.


  • +

    Amazing performance

  • +

    Don't need a new motherboard


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    Price went up

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    No included cooler

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AMD Ryzen 9 5900X: two minute review

Thanks to the AMD Ryzen 9 5900X and the rest of the Ryzen 5000 series, there might be a new gaming processor champion on the market. 

The war between AMD and Intel has raged for years over the best single- and multi-threaded performance, and it was always believed that you go with AMD for top-notch multi-threading for professional and creative applications. 

But, if you’re trying to squeeze every ounce of performance for the best PC games, it was assumed that Intel was the best CPU for the job.

But the AMD Ryzen 9 5900X may have changed all that. This CPU might just be the best available option. It’s just as capable with single-threaded tasks as it is with multi-threaded ones. 

AMD’s Ryzen 5000 presentation made this clear, as the company zeroed in on gaming, with creative applications taking a back seat. As a result, the company might have created the best gaming CPU you can get right now.

Rounded out by PCIe 4.0 support, the Ryzen 9 5900X is now the flagship product among the best AMD processors, and with it, there’s really no reason to buy an Intel processor for that gaming PC you’re building. 

AMD Ryzen 9 5900X: price and availability 

The pins of an AMD Ryzen 9 5900X

The Ryzen 9 5900X fits into the same AM4 slot as Zen 2 chips (Image credit: Future)
  • How much is it? MSRP is listed at $549 (about £420, AU$760)
  • When is it out? It is on sale now
  • Where can you get it? You can get it in the US, UK, Australia, and elsewhere

The AMD Ryzen 9 5900X is available today for $549 (about £420, AU$760). That is a $50 (about £30, AU$40) price jump from the 3900X, which launched for $499 (about £390, AU$720) back in July 2019. That 10% price jump is a tough pill to swallow, but it's largely in part due to the lack of competition from Intel. 

For comparison's sake, the Intel Core i9-10900K launched for $488 (about £400, AU$750) back in May 2020, and didn't manage to meaningfully tackle the Ryzen 9 3900X. However, with that processor, Intel did at least manage to hold on to its single-core crown for a little while. 

But, because the AMD Ryzen 9 5900X trounces the Core i9-10900K so thoroughly, AMD's new processor kind of exists in a realm of its own, where the price hike at least starts to seem justified. It's hard to argue for the price bump when it's among the best processors ever made. 

At this price point, there is nothing that can even approach the AMD Ryzen 9 5900X, so if you're in the market for a high-end consumer processor, there really isn't any other choice right now. 

AMD Ryzen 9 5900X: features and chipset

  • Same AM4 Socket as Ryzen 9 3900X
  • PCIe 4.0 support
  • 7nm architecture

The AMD Ryzen 9 5900X is built on the Zen 3 architecture, which on a surface level may look similar to Zen 2 – they're both 7nm, after all. However, AMD has redesigned the architecture from the ground up to increase IPC performance and efficiency to the point where it leaves no prisoners. 

The biggest difference in architecture from Zen 2 to Zen 3 is that instead of having two Core Complexes (CCX) per compute die (CCD), each CCD only has one CCX, with each CCX having up to 8 cores, rather than 4 cores on Zen 2. This change not only cuts down on latency when cores are communicating with each other, but it also means that each CCX has access to a full 32MB of L3 cache, rather than being limited to 16MB of the stuff on Zen 2.

This means that while the Ryzen 9 5900X has the same amount of L3 Cache as the Ryzen 9 3900X at 64MB, each core has direct access to 32MB on the 5900X, rather than 16MB on the 3900X.

Because cache is so important to gaming performance, this change, along with the higher clock speeds, massively boosts gaming performance. In fact, as we'll explore later, AMD has boosted performance across the board here.

AMD Ryzen 9 5900X key specs

Socket: AM4
Base frequency:
Boost frequency:
L3 cache:
AMD Zen 3
Process node:
7nm (TSMC)
PCIe: 4.0
Max RAM: 128GB DDR4-3200 (Dual-channel)
Integrated Graphics: No
Unlocked: Yes

As far as raw specifications go, the AMD Ryzen 9 5900X is a 12 core, 24 thread processor, with a boost clock up to 4.8GHz, with a 3.7GHz base clock. It has the same 105W TDP as the Ryzen 9 3900X, and in our testing only reached a max of 142.27W, compared to the 145.3W that the Ryzen 9 3900X reached in the same testing suite. This simply demonstrates just how much more efficiency AMD was able to squeeze out of Zen 3. 

Another huge winning point here is that we don't have a new chipset this time around. X570 motherboards are still the top-end boards for AMD Ryzen 5000 processors, which is excellent news for anyone looking to upgrade from an older Ryzen processor, and it also means that we won't run into any major stock issues. 

Of course, in order to upgrade to one of these processors, you'll still need to update your BIOS, though new motherboards will ship with a Ryzen 5000-ready BIOS preinstalled. To be safe, though, you're going to want to check to make sure the motherboard you're buying has the latest BIOS installed before you try to install it. 

But that compatibility goes further than just 500-series motherboards, certain X470 and B450 motherboards will also support Ryzen 5000 processors like the Ryzen 9 5900X, though not all of them. Again, you're going to want to check the manufacturer's website to make sure the motherboard you're looking at will be compatible. 

If you're a new AMD user, one thing you're going to want to be aware of is how temperatures work. Rather than having one static boost target like an Intel processor, AMD Zen 3 processors will constantly be trying to maximize performance. This means that you may see uncomfortably high temperatures, especially if you're pushing the processor hard. 

For instance, in our testing, the AMD Ryzen 9 5900X reached a maximum temperature of 86°C – and that's with a 360mm AIO cooler attached. Don't worry, that's just how Ryzen is designed. AMD has told us that the new processors may peak around 98°C, and that it's expected. Your processor isn't going to burst into flames. 

At the same time, Intel's processors run much cooler. In the same suite of tests with the same cooler, the Intel Core i9-10900K peaked at just 73°C. Again, this is just a difference in how these coolers are designed, but AMD's processors could lead to more hot air circulating around your case, depending on the cooler you're using. 

On that topic, AMD isn't including a Wraith cooler in the box anymore, which means you're going to have to invest in an aftermarket cooling solution, so we'd advise going with at least a 240mm AIO liquid CPU cooler or a thicc air cooler like the Noctua NH-U12A.

AMD Ryzen 9 5900X: performance

  • Exceptional gaming performance
  • Dominates multi-threaded workloads
  • Improved single-threaded performance

The AMD Ryzen 9 5900X is the fastest processor we've ever tested on a mainstream platform, and it's not even that close. In all but one of our tests, the Ryzen 9 5900X was significantly ahead of not only its predecessor, the Ryzen 9 3900X, but ahead of its main competition – the Intel Core i9-10900K.

We focused our testing around the best PC games going this time around, as that's the core use-case AMD is now championing – and with good reason. 

In the most CPU-demanding game in our testing suite, Assassins Creed Odyssey, the AMD Ryzen 9 5900X beats out the Intel Core i9-10900K by 8%, pushing it above 80 fps. However, in this test it's pretty much even with the AMD Ryzen 9 3900X. 

The Ryzen 9 5900X has a bigger departure in Total War: Three Kingdoms, however, which is a game that has always favored Intel processors. In this game, the AMD Ryzen 9 5900X averages 116 fps at 1080p with the Ultra quality preset, beating out the Intel Core i9-10900K's 108 fps at the same resolution and quality. That's a 7% difference, there, too. 

Test system specs

These are the systems we used to test the desktop CPU performance in this review:

All CPUs:
CPU Cooler:
Cooler Master Masterliquid 360P Silver Edition
Graphics card:
Nvidia GeForce RTX 2080 Ti
32GB HyperX Predator RGB @ 3,000MHz
ADATA XPG SX8200 Pro @ 1TB
Power Supply:
Phanteks RevoltX 1200
Case: Praxis Wetbench

Intel 10th Gen:
MSI MEG Z490 Godlike

Intel 9th Gen:
Motherboard: MSI MEG Z390 ACE

AMD 3rd Gen:
 X570 Aorus Master

AMD Ryzen 9 5900X and Ryzen 7 5800X:
AsRock X570 Taichi

The only place where Intel holds a lead is in the Time Spy physics test. For this test, we isolate the CPU score, rather than report the overall score. The Ryzen 9 5900X scores 12,885 points to Intel's 13,888 points. That's a 7% lead in Intel's favor, turning the tables in that synthetic gaming workload. However, what's impressive is that it's now even with the Ryzen 9 3950X, the flagship of the previous generation. 

Moving on to pure CPU workloads, the Ryzen 9 5900X unsurprisingly wipes the floor with the Core i9-10900K in multi-core workloads – but that was true of the Ryzen 9 3900X. However, the Ryzen 9 5900X, in the GeekBench 5 multi-core test is now 24% faster than the Intel Core i9-10900K, up from the 11% lead enjoyed by the Ryzen 9 3900X. 

In Cinebench R20, which simulates rendering for creative applications, the multi-core lead expands to a whopping 31%. The smallest lead in pure CPU performance comes in the SISoft Sandra CPU Arithmetic test, where the Ryzen 9 5900X is just 18% faster – but that's still a significant lead. 

The biggest story here is the significant jump in single-core performance, facilitated by that ground-up redesign in the Zen 3 architecture. In the Cinebench R20 single-core test, the AMD Ryzen 9 5900X scores 618 points, up from the 518 scored by the Ryzen 9 3900X, a 19% gen-on-gen increase. The Intel Core i9-10900K scores 522 points in this test, 18% slower than AMD.

That story repeats throughout all of our synthetic single-core tests. The Intel Core i9-10900K is 21% slower in Cinebench R15 single-core, 9% slower in GeekBench 4 and 12% slower in GeekBench 5. 

AMD has finally claimed the single-core performance crown from Intel. That's heavily reflected in benchmarking software, but what's more impressive is how that's reflected in raw gaming performance. With Zen 3, AMD set out to create the best processor for gaming and in every test we've run, Team Red has absolutely hit that target. 

Even more importantly, this marks one of the biggest generational improvements we've ever seen in processors. Intel has been adding small increases with each generation, but the Ryzen 9 5900X smashes past the Ryzen 9 3900X. In fact, while we would normally advise that folks don't upgrade their processor after just a single generation – and still largely hold that opinion – there's a genuine case to be made to upgrade to the 5900X from the 3900X, especially if gaming is large portion of what you do with your PC. 

This is especially true when you consider the massive generational leaps experienced in the best graphics cards. When you look at how the RTX 3080 behaves at 1080p and 1440p, you need a strong gaming CPU to pair with it – the Ryzen 9 5900X would make an excellent gaming companion.

Should you buy an AMD Ryzen 9 5900X?

The retail packaging for the AMD Ryzen 9 5900X on a coffee table

The AMD Ryzen 9 5900X is available now (Image credit: Future)

Buy it if...

You want the best processor for gaming
The AMD Ryzen 9 5900X is an incredibly powerful processor for gaming, bringing single-core performance that goes way beyond what last-generation CPUs brought to the table. A large portion of games should see a massive performance increase.

You need something that can do creative work
Ryzen is Ryzen, and with 12 cores and 24 threads, the AMD Ryzen 5900X is an absolute beast for multi-core workloads. The massive boost to single-core performance helps to increase multi-core performance – after all if every core is faster, the entire processor will obviously benefit. 

You want a nice upgrade from Ryzen 2000 or 3000
Because the AMD Ryzen 9 5900X features such a huge jump in single-core performance over the Ryzen 9 3900X, it's genuinely worth the upgrade, especially if one of the main things you're doing with your PC is playing PC games.

Don't buy it if...

You're on a budget
The Ryzen 9 tier of processors is already a no-go for anyone looking to build a reasonable machine, especially when the Ryzen 7 5800X comes so close in games, but because AMD added an extra 10% to the purchase price, the Ryzen 9 5900X is even more expensive this time around. 

You need an included cooler
The AMD Ryzen 9 5900X doesn't have a cooler in the box, not that we would recommend using it even if it did. If you don't have the cash to invest in a third-party CPU cooler, you may want to look elsewhere.

Also consider


AMD Ryzen 7 5800X3D
When we reviewed the AMD Ryzen 9 5900X, 3D V-Cache wasn't a thing, but with the introduction of this new AMD technology, the Ryzen 7 5800X3D absolutely goes toe-to-toe with the Ryzen 9 5900X for gaming, and it's even less expensive as well. It still falls behind considerably in other workloads though, so only consider this if you are looking for the best pure gaming CPU out there.

Read the full AMD Ryzen 7 5800X3D review


Intel Core i9-12900K
In the past year, Intel has launched its Alder Lake processors, and the flagship Core i9-12900K is indisputably the best processor on the market right now. Whether it's gaming or any other workload, this processor will do just as well if not far better than the Ryzen 9 5900X, but the cost of a new motherboard and new RAM as well as the processor could make this a very expensive alternative.

Read the full Intel Core i9-12900K and Core i5-12600K review

Jackie Thomas

Jackie Thomas is the Hardware and Buying Guides Editor at IGN. Previously, she was TechRadar's US computing editor. She is fat, queer and extremely online. Computers are the devil, but she just happens to be a satanist. If you need to know anything about computing components, PC gaming or the best laptop on the market, don't be afraid to drop her a line on Twitter or through email.

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