June 20, 2024


Sapiens Digital

AMD Ryzen 9 3900XT – Review 2020

15 min read

In PC-component releases over the past year, we’re starting to see a frequent theme: the “silicon tune-up.” AMD’s Ryzen 9 3900XT desktop CPU ($499) follows in the footsteps of product launches like the Intel Core i9-9900KS and the “Super” line of graphics cards from Nvidia, offering up modestly improved silicon in a familiar package. Here, that’s a refinement of the Editors’ Choice-winning Ryzen 9 3900X, a superb-value 2019 CPU for content creators. While current owners of the Ryzen 9 3900X won’t see enough incentive to upgrade to this slightly better version, anyone who has been holding off on AMD’s excellent third-generation Ryzen CPUs has another strong option to consider. The performance gap in our benchmark testing (and AMD dropping its traditional bundled cooler) may not justify the higher price for the Ryzen 9 3900XT over its 3900X kin. But if you’re a creator on the hunt for the peak speed that 7-nanometer (7nm) lithography can deliver for around $500, this chip is it.

AMD Takes the ‘Super’ Route

The last 12 months have been a banner year for AMD, there’s no denying that. The company has successfully jumped its desktop-CPU manufacturing process from 12nm in the previous generation of Zen-based desktop processors to 7nm in the latest iteration, “Zen 2.” And the benefits brought by that shift are being enjoyed by everyone down the line.

AMD Ryzen 5, 7, 9 XT CPUs (x3) Box

Well everyone except Intel, maybe. While AMD’s transition to a new lithography has been reasonably smooth, Intel’s attempts to move beyond its current 14nm desktop-CPU architecture could be categorized as “anything but.” The company has been struggling with a transition to 10nm on desktop. As of this writing, there’s been no official word from the company on when, if ever, its desktop CPUs will see 10nm process technology employed.

Intel’s just-released 10th Generation desktop chips, in its “Comet Lake-S” line (headed up by the Core i9-10900K), use a refinement of the company’s long-running 14nm process. Things are a little further along with its mobile processors; the upcoming “Tiger Lake” line of CPUs, set to replace the laptop-centric family of 10th Generation “Ice Lake” CPUs, will have 10nm lithography this year, though Ice Lake already did last year. But note that some of Intel’s other 10th Generation laptop chips, the beefier “Comet Lake-H” line of CPUs that go into powerful laptops and gaming models, are still on a form of 14nm, like the desktop chips.

AMD Ryzen 5, 7, 9 XT CPUs (x3) Box 2

Meanwhile, AMD has been busy the last few months preparing three “refined” versions of 7nm CPUs it released last year at this time. The XT line of Ryzen chips (the Ryzen 5 3600XT, the Ryzen 7 3800XT, and the Ryzen 9 3900XT reviewed here) are “new” CPUs from AMD with very familiar names…but don’t get them confused with a graphics card. (AMD’s 2019 “Navi” Radeon graphics card releases also end in “XT,” confusingly enough.) According to AMD, all the desktop processors released under the “XT” moniker represent improvements in the 7nm production process, showcasing all that its engineers have learned about the new lithography since July 7 of last year. And don’t call it “Zen 2+” either; the company was clear on that.

Each of the three XT chips sees a slight (emphasis on “slight”) gain in its maximum boost frequency on single-core performance (4.6GHz to 4.7GHz on the Ryzen 9 3900XT, for example). And from a spec-to-spec perspective, that’s the only improvement on these CPUs versus the three respective chips they’re named after. AMD also emphasizes that these CPUs will supplement, not replace, the non-XT versions. The Ryzen 5 3600X, the Ryzen 7 3800X, and the Ryzen 9 3900X will continue to be sold.

Intel did a similar thing last year with its mainstream desktop CPUs. The chip giant released the Core i9-9900KS back in October of 2019, just a few months after Nvidia started this “tune-up” trend with GPU launches like the GeForce RTX 2080 Super. But the 9900KS chip represented only a single, limited-stock option that didn’t stay widely available for much longer than it took for Intel to launch it. You can still find it at this writing, but it’s not common.

Intel Core i9-9900KS Box

So, in the second half of 2020, as noted, 14nm for mainstream Intel desktop chips has persisted. It’s the staple lithography behind Intel’s new desktop 10th Generation Core chip stack, and the flagship-entry Core i9-10900K represents the closest point of comparison for AMD’s Ryzen 9 3900XT at this level of the game.

There’s no sign (just yet, anyway) of an Intel Core i9-10900KS in the rumor-sphere to compete with this XT chip, but given the stellar gaming results of the 9900KS, don’t be surprised if one eventually emerges. The practice of remarketing the best silicon samples on the tail end of a product’s lifecycle might become a viable strategy for both chip makers moving forward.

The Ryzen 9 3900XT vs. the Core i9-10900K: AMD vs. Intel at $500

At the $499 MSRP price tier, we have a lot of options to compare these days. It seems both AMD and Intel have agreed that $500 represents just about the threshold of what the mainstream is willing to shell out at the top end, though each offers something a bit different for the money…

Ryzen 9 3900XT Spec Comparison

The real question lies here: The Intel Core i9-10900K wasn’t out yet when the Ryzen 9 3900X dropped, so how does the 3900XT stand up to the challenge set by Intel while AMD was sleeping?

The Ryzen 9 3900XT is a 12-core, 24-thread desktop CPU with a base clock of 3.8GHz and a maximum boost clock of 4.7GHz (up from 4.6GHz in the original Ryzen 9 3900X), 6MB of L2 cache and 64MB of L3. The $499 Intel Core i9-10900K, however, is only a 10-core/20-thread chip.

The 3900XT still leading on cores, and that’s a no-brainer. The same yield percentage that made it possible to drop the price of cores for the first pass of 7nm-based processors has continued into the XT line, and try as Intel might, the chip giant still can’t find a way to keep up profitably with AMD on the path to cost-per-core dominance. (That said, the Core i9-10900K is up from eight cores/16 threads in the Core i9-9900K, which is a step in the right direction.) 

One thing to note: You do get an integrated graphics processor (IGP) with most chips in Intel’s line, including the Core i9-10900K, but a bigger question is whether you really need an IGP with a Core i9-10900K. If you’re buying at this level and you’re sticking with Intel, you’re probably interested in one thing: the fastest gaming frame rates possible. This suggests that you’ve also paid at least a fraction, if not a multiple, of what you spent on the Core i9-10900K on your graphics card, making the IGP moot. (Intel also offers an IGP-less Core i9-10900KF for a slightly lower list price, but it was not widely available at this writing.) The decision to shed the IGP in favor of more compute cores on the die favors AMD here for most shoppers.

Continuing down the line of ticked boxes in AMD’s column: socket compatibility. We wouldn’t expect the need for a socket upgrade for a release of chips so close in characteristics to their predecessors, and AMD doesn’t make you buy a new motherboard. The XT CPUs are all Socket AM4 chips. Indeed, that same advantage even held with the original Zen 2 launch; with some mild caveats, those Ryzens were backward-compatible with older Socket AM4 motherboards, too.

Buyers who want to adopt the Intel Core i9-10900K, though, don’t have it as easy. The move from LGA1151 in 9th Generation chips to LGA1200 in 10th Generation means a new mobo, and more cost to move to that platform that could be spent on something like a GPU.

Intel Core i9-10900K Box Shot

So the Ryzen 9 3900XT wins on cores, cost, and compatibility, but where it slips is on maximum boost frequency. Intel still has the boost-frequency sprint advantage, one that it has maintained for a number of years. For the release of the Core i9-10900K, the company cranked things up even higher than usual, jumping from 4.6GHz on the Core i9-9900K up to a very respectable 5.3GHz on the Core i9-10900K. (That’s the maximum boost turbo single-core frequency.) At least from specs, Intel looks to retain its (admittedly slimmer-by-the-year) lead over AMD in single-core pep.

One quick note: That increased single-core horsepower does come at the cost of both heat and power draw. The Ryzen 9 3900XT retains the same 105-watt thermal design power, or TDP, rating of the 3900X, while Intel saw its power requirements jump, from 95 watts in the Core i9-9900K to 125 watts in its i9-10900K successor.

Ultimately, where things get a bit cloudier for AMD is…in AMD versus AMD. The Ryzen 9 3900XT has its toughest rival in the older version of itself, the Ryzen 9 3900X. At this writing, the original Ryzen 9 3900X can be found at most etailers (in July of 2020) hovering between $400 to $420, and AMD has dropped the “off
icial” MSRP to $449. This means at the best of times, the Ryzen 9 3900X could sell for a full $100 less than the $499 MSRP of the Ryzen 9 3900XT.

Ryzen XT Underside

One further wrinkle with the 3900XT, alluded to up top, is cooling. Until the XT line launched, all 7nm Ryzens below the high-end 16-core Ryzen 9 3950X came bundled with an able AMD Wraith fan-based air cooler of one kind or other. But the Ryzen 9 3900XT is one of the few instances AMD won’t be featuring a fan cooler in the box with a Ryzen chip. That’s also the case with the Ryzen 7 3800XT. In our reviewers’ notes, AMD recommended that both of these CPUs would be optimally tested (and therefore optimally run at home) on liquid cooling systems, or on a specific selection of high-end Noctua air coolers.

If you don’t own an AM4-compatible liquid cooler, that’s not an small sum to leave off the cost of ownership. A midrange liquid cooling system goes for just about $100, give or take a Jackson, while the recommended Noctua coolers start at around $60. So now we’re out potentially as much as $200 over the price of a Ryzen 9 3900X with its included Wraith Prism cooler. Let’s see how that extra cost shakes out, relative to our benchmarks.

Testing the Ryzen 9 3900XT: AMD Keeps Its Content-Creator Crown

We kept the AMD Ryzen 9 3900XT cool under pressure using a closed-loop NZXT Kraken liquid cooling system with a 240mm radiator, and installed it onto a MSI MEG X570 Godlike AM4 motherboard with two of the DIMM slots populated with 16GB of G.Skill DDR4-3600 memory. A 1TB Addlink S70 PCI Express Gen 3 NVMe M.2 SSD was the boot drive, and an Nvidia GeForce GTX 2080 Ti Founders Edition card handled video output during the CPU tests. For all tests, we ran the memory at its maximum 3,600MHz speed, using the Godlike board’s top supported XMP profile.

Thankfully, everything worked right out of the box with the 3900XT…no critical BIOS updates or midnight-hour benchmark crashes during our testing. Speaking of, let’s jump in.

Cinebench R15 and R20

Among the most widely used predictors of a CPU’s relative performance are the Cinebench R15 and R20 benchmark tests, which offer a good muscle measure for demanding multi-threaded content-creation apps. These are thoroughly CPU-centric tests that gauge both the single-core performance and the multicore performance of a processor when it is stressed. The resulting scores are proprietary numbers that represent the CPU’s capabilities while rendering a complex 3D image.

AMD Ryzen 9 3900XT (Cinebench R15)AMD Ryzen 9 3900XT (Cinebench R20)

In content creation, pound-for-pound, this test tells the basic story. As was the case with the launch of the third-generation, 7nm Ryzens, AMD offering a 12-core CPU at the same price as Intel’s top-end competition (the eight-core Core i9-9900K back in 2019, the 10-core Core i9-10900K now) is a big advantage when the test is an all-cores-engaged drag race. And serious content-creation software tends to fall into this category.


For another kind of real-world look at single-core performance, we use a, shall we say, vintage version of Apple’s iTunes to encode a series of music tracks. It remains in our test lineup simply as a representative of legacy software we all use from time to time that has not been heavily optimized for multicore operation.

AMD Ryzen 9 3900XT (iTunes)

No surprises here. AMD continually proves itself in the $500 bracket as the content creator’s best friend, but the single-core workloads don’t quite up when stacked against Intel’s latest offerings.


The POV-Ray benchmark is a synthetic, highly threaded rendering test that offers a second opinion on the Cinebench results. This test uses ray tracing to render (offscreen) a three-dimensional image. (Note that it doesn’t use the ray tracing features of Nvidia’s RTX-class GPUs; this is purely CPU-focused.) We run all-cores and single-core variants.

AMD Ryzen 9 3900XT (POV-Ray)

POV-Ray results show both sides of the spectrum for AMD, much like Cinebench, reminding everyone that even on its best single-core-boost behavior the Ryzen line can’t keep up with Intel’s current-gen single-core performance. But the Ryzen 9 3900XT dominates the Intel Core i9 mainstream offerings at its price point when all cores are engaged.

Handbrake and Blender

As an all-core rendering benchmark, the Handbrake test is a great indicator of how well a processor will handle tasks like video editing, video rendering, and video conversion, as these kinds of apps tend to chow down on all the cores and threads they can get…

AMD Ryzen 9 3900XT (Handbrake)

Solid work here by the 3900XT versus the Core i9 competition (the Core i9-10980XE Extreme Edition chip, thrown in for contrast, is a $979 processor in the elite Intel Core X-Series, not really comparable), but one odd note: The Ryzen 9 3900XT just barely loses to its non-XT variant. (We ran it three times, to be sure.) But it’s still well within the margin of testing error.

Meanwhile, the shorter Blender test, as run with our test file, is mostly useful for highlighting the differences between low-end and high-end chips, and the similarities between chips within these two categories.

Blender is a bit more difficult to parse among these tightly priced chips, but those precious seconds can mean a lot of saved render time for larger animation and VFX studios.


And here we have the 7-Zip file-compression benchmark, another thread-happy, CPU-intensive task…

AMD Ryzen 9 3900XT (7-Zip)

The story for the 7-Zip benchmark remains as true here as it has for every mega-core monster in the Ryzen family: the more cores and threads, the more dominant the score. The real surprise here is just how much higher the Ryzen 9 3900XT scored than the original 3900X, but unless you’re compressing files on a massive scale each day, you probably won’t see these benefits translate into the real world.

Onward to Gaming: Ryzen 9 3900XT Frame Rates

On content creation? The Ryzen 9 3900XT is a real monster for the money. But like the top-end Ryzens of 2019, the Ryzen 9 3900XT can’t quite keep up with its price-mirrored equivalents from Intel when it comes down to gaming.

Across the board, the Intel Core i9-10900K proves itself the superior gaming workhorse on raw frame rates, and even though most of the substantial frame-rate wins it clocks are well above 240fps, which is to say, above the 240Hz monitor threshold (especially in titles like Counter Strike: Global Offensive and Rainbow Six: Siege), it still shows itself to be a formidable rival for AMD in the pursuit of pure fps results.

Gaming Desktop CPUs Discreet Graphics Testing

While there’s been no solid confirmation that a single-CCX, four-core design is the ultimate path forward for AMD’s forthcoming Zen 3-based CPUs focused toward gamers, the results can’t be ignored. At 1080p, the $120 Ryzen 3 3300X, with its single-CCX design, comes just within spitting distance of the $499 Ryzen 9 3900XT, and it regularly keeps pace with both it and the Intel Core i9-10900K at 4K resolution. The CPU tends to be a bigger factor at lower resolutions, while the GPU tends to be the limiter at high resolutions like 4K. You have to really want the extra cores and threads from the 3900XT for other things than gaming to justify it.

At this pricing tier, the Ryzen 9 3900XT continues to trail the best of Intel’s offerings, an admittedly expected result (no matter how fine-tuned the silicon). The 3900XT proves that even with all the refinements made to the underlying production process of Ryzen chips built off Zen 2, the architecture of its higher-core-count chips will always lead to increased latency. It’s the primary reason why the cheap Ryzen 3 3300X, with its single-CCX design, excels in gaming for the price in ways that other Ryzen chips simply can’t.

Overclocking and Thermals

When we reviewed the first line of third-generation Ryzen chips, we found the original Ryzen 9 3900X didn’t leave a whole lot of headroom to overclock with.

That story seems to have changed ever so slightly in the case of the Ryzen 9 3900XT, at least with the sample we got. After some custom tuning in AMD’s Ryzen Master overclocking software, it was capable of retaining a stable overclock of 4.15GHz on all cores, pushing the Cinebench R20 score from 6,915 on the stock settings to 7,319 in overclock.

That’s respectable, though again, we had a liquid cooler on the chip; that’s an extra expense if you don’t have one already. Also, for reference, the 16-core/32-thread Ryzen 9 3950X, the next chip up AMD’s hierarchy, scored 9,104 on the same test. So don’t get too ambitious; overclocking your Ryzen 9 3900XT won’t bring you within remote striking distance of getting a 3950X on the cheap.

AMD Ryzen Master Overclocking Ryzen 9 3900XT

Also, bear in mind, that’s Cinebench. And that’s where the differences in overclocking ended between the two chips. A tendency of the original Ryzen stack makes its return here: When any amount of overclocking is applied to the chip, even by a few megahertz on the front four cores, games don’t see much change, or may actually lose frames instead of gaining them. Overclocking doesn’t offset the fundamental architectural limits of the chip.

Also, the Ryzen 9 3900XT gets a little hotter under the collar than its 3900X kin. The Ryzen 9 3900X often averaged in the mid-60-to-mid-70-degrees Celsius range, whereas this chip could go as hot as 81 degrees C during intense workloads, a number that crept up to 83 degrees C once the overclock was applied. Anyone who plans to put the 3900XT through extended heavy workloads will want a comparably heavy-duty liquid cooling system to handle it at its hottest. And that’s a lot more money outlay for a modest boost.

Solid, But What About Zen 3 Around the Corner?

With the launch of Zen 3 purportedly coming later this year (a few weeks back, an AMD spokesperson insisted pointedly that it is still on track for 2020), current owners of third-gen Ryzen Zen 2 CPUs probably will want to sit out the XT wave. So should upgraders who are still waiting with a chip on an old, pre-AM4 platform at home.

While the performance gains of the 3900XT over the 3900X are apparent, they’re not big enough to warrant the $50 to $100 price difference, plus the possible cost of an aftermarket cooler. Even with a full overclock on a 240mm liquid cooler (its own expense), the best-case scenario is that creators in particular (gamers, sit this one out) will see about a 10 percent gain in performance for almost a 20 percent jump in cost, and that’s without factoring in the cooler cost.

AMD Ryzen 9 3900XT

The Ryzen 9 3900X (and now the Ryzen 9 3900XT) remain top choices for content creators at their respective price tiers, no doubt. Pure gamers, not so much: They could get functionally close-enough frame rates with the Ryzen 5 3600XT, and they might even be just as happy with the $120 Ryzen 3 3300X if having lots of cores and threads in their pocket doesn’t matter to them.

All in all, the AMD Ryzen 9 3900XT is a powerful option at $499, and a great showing overall for AMD in its price range (just as the original Ryzen 9 3900X was when it came out last year). If cores and threads for the money matter more to you than game frame rates, and you own an AM4 cooling solution already, it’s a very solid buy. But it’s hard to ignore the still-fierce, still-available, and still-cooler-equipped Ryzen 9 3900X…as well as the Zen 3 launch on the horizon.

AMD Ryzen 9 3900XT Specs

Core Count 12
Thread Count 24
Base Clock Frequency 3.8 GHz
Maximum Boost Clock 4.7 GHz
Unlocked Multiplier? Yes
Socket Compatibility AMD AM4
Lithography 7 nm
L3 Cache Amount 64 MB
Thermal Design Power (TDP) Rating 105 watts
Integrated Graphics None
Bundled Cooler None

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