AMD Ryzen 9 3950X vs Intel Core i9-9900K: The Battle for Mainstream Supremacy

For years, Intel's flagships were the only solution if you wanted the most powerful processor that money could buy. AMD, while it always offered good value at the low end, simply could not compete on the high end. That is until the red team turned the tide with its Zen architecture that underpins the company’s Ryzen and Threadripper CPUs.

AMD flipped the processor world on its head two years ago, and it continues to disrupt the industry. Recently, the company launched the Ryzen 9 3950X, which is the first mainstream processor to offer 16 cores for clobbering multi-threaded workloads on a mainstream platform. 

The 3950X is more expensive than Intel's rival eight-core Core i9-9900K, but that's expected. Intel does have its Core i9-9900KS on offer, but that limited-edition chip won't be available after the holidays (according to Intel). Even with the $250 price disparity between the two chips, both of these processors represent the best each company has to offer on a mainstream platform. 

As such, today, we'll put the Core i9-9900K and the Ryzen 9 3950X to the test to see which processor reigns supreme on the company's mainstream platforms. 

Features

AMD’s Ryzen 9 3950X is the pinnacle of the company’s mainstream processor lineup. It’s built on the Zen 2 microarchitecture, which uses the Infinity Fabric interconnect to combine multiple chiplets to form high core-count CPUs. Zen 2 also supports the PCIe 4.0 specification, which doubles the available bandwidth for PCIe devices such as NVMe drives and graphics cards.

The Ryzen 9 3950X features two 7nm eight-core chiplets, just like the Ryzen 9 3900X. However, unlike the 3900X, this processor comes out of the factory with every core enabled. Amazingly, AMD didn’t have to lower the peak clock speeds, and it didn’t increase the 105W TDP rating. The 16-core 3950X comes out of the box with a 3.5 GHz base clock and a 4.7 GHz boost clock, although, as we recently discovered, the boost frequency isn’t necessarily consistent across all cores,

The Ryzen 9 3950X also includes 64MB of L3 cache, which is twice as much cache memory as the previous-gen Ryzen chips, and four times as much cache memory as Intel’s desktop chips.

Speaking of memory, Zen 2 processors officially support dual-channel DDR4-3200, and the Ryzen 9 3950X is no exception.

The features that the Ryzen 9 3950X brings to the table really haven’t been seen at this price point before. As we wrote in our review of the processor; “to say this chip blurs the lines between the mainstream desktop and HEDT is an understatement: In reality, it brings HEDT-class performance to the friendlier pricing of mainstream motherboards, placing it in a class of its own.“

Intel’s Core i9-9900K doesn’t move the HEDT needle closer to the mainstream in the same way that AMD’s Ryzen 9 processors do, but it is still a compelling option for certain functions because of its sheer clock speed. Intel is taking a brute-force approach to staying relevant in the enthusiast PC market. The company is struggling to shrink its designs to smaller process nodes, with several delays to its planned 10nm desktop processors preventing Intel from following AMD’s lead in terms of core counts. As such, the current CPU lineup is built on Intel’s 14nm++ process.

The Core i9-9900K is an 8-core, 16-thread processor that operates at a maximum frequency of 5 GHz. The 9900K offers a base clock of 3.6 GHz, can boost to 5 GHz on up to two cores, and up to 4.7 GHz on all eight cores. And unlike AMD’s processors, the core frequency does not waver between cores: all cores on the chip can reach the 5.0 GHz threshold.

The 9900K is rated at a 95W TDP and also includes solder TIM (sTIM), to facilitate heat dissipation.

Like the rest of Intel’s 9000-series processors, the Core i9-9900K features support for dual-channel DDR4-2666 memory. It also offers built-in UHD 630 graphics so you don’t need a discrete graphics card to build a system with this CPU, though it is noteworthy that you'll need a discrete graphics card for even mid-range gaming. The i9 processors also include 16MB of L3 cache memory.

Winner: AMD. When it comes to features, AMD’s Ryzen 3000 series outclasses Intel’s 9th Gen Core series with a variety of modern features. The smaller 7nm process allows AMD to pack more cores and more cache memory into a single socket, and the new PCIe 4.0 standard gives you far more bandwidth for modern accessories and SSDs.

Cooling

AMD cranked up the core count of the Ryzen 9 3950X, but at the cost of diminished all-core clock speeds. To keep the temperatures in check with an extra four cores under the lid, AMD reduced the base core clock of the 3950X to 3.5 GHz. Under load, the flagship Ryzen can boost to 4.7 GHz, but you will need a beefy cooling solution to sustain such speeds.

Unlike other mainstream Ryzen processors, the Ryzen 9 3950X doesn't come with a bundled cooling solution. AMD recommends using a 280mm AIO cooler to keep the cores chilled, but we found even that to be somewhat inadequate. In our tests of the 3950X, our Corsair H115i struggled to keep core temperatures low enough to maintain the factory boost frequency. To extract the full potential of a 3950X, you're best with a custom water-cooling loop.

The story is quite different on Intel’s side of the court. Even though the Core i9-9900K's primary advantage is its clock speeds, the chip doesn’t put off nearly as much heat as AMD’s counterpart. That said, don’t think you can skimp out on your cooling here: Liquid cooling is still a must.

The Corsair H115i that stumbled under the weight of the Ryzen 9 3950X handled the load from our Core i9-9900K and allowed the chip to run at an overclocked all-core clock speed of 5.0 GHz. 

Winner: Tie. Both AMD’s Ryzen 9 3950X and Intel’s Core i9-9900K push the limits of modern CPU coolers, but Intel’s chip is a bit more forgiving. You can get away with an off-the-shelf 240mm watercooler if you run a 9900K, but if you’re looking to extract the utmost performance from a 3950X, you might consider a beefier AIO or custom water cooling loop.

However, the Ryzen 9 3950X comes with eight more cores than the 9900K, a neat doubling, and the increase in thermal dissipation isn't linear, meaning heat output doesn't double. Given the extra performance to be had with the 3950X, its increased thermal output is acceptable, yielding a tie in this section.  

Overclocking

AMD’s Ryzen platform does many things well, but manual overclocking has never been one of them. AMD optimizes its chips so heavily to offer the highest possible out-of-the-box performance that tweaking parameters to coax more out of these high-core count chips often results in increased multi-thread performance, but decreased single-thread performance.

In our tests, we had trouble maintaining a 4.3 GHz overclock on all cores. An 800 MHz bump for multi-threaded applications is nice, but it comes at the cost of a 400 MHz decrease for single-threaded tasks. Using AMD’s automated Precision Boost Overdrive feature maintains the stock single-thread boost clock, but half the fun of overclocking is tweaking the parameters yourself.

Intel’s architecture is much better suited to overclocking enthusiasts that wish to tinker with their system’s settings. Intel also has a one-click automated Intel Performance Maximizer overclocking software that takes the elbow grease out of overclocking, which is a nice feature for less-savvy users.  

In our tests, when paired with a suitable cooling solution, we were able to extract another 300 MHz out of each core, to give us an all-core clock speed of 5.0 GHz (albeit with a -2 AVX offset), with a beefy off-the-shelf Corsair H115i cooler.

Winner: Intel. AMD’s Ryzen processors have never offered much extreme overclocking potential with conventional cooling methods, and the Ryzen 9 3950X is no exception. While you can extract a bit more performance out of a Ryzen 9, Intel’s platform is obviously superior for overclocking enthusiasts. 

Motherboard Options

The motherboard selection for AMD’s Ryzen 9 3950X is surprisingly vast. According to AMD, the X570, X470, and B450 chipsets all support the company’s top-dog processer. However, some X370 boards, such as the Asus Crosshair VI Hero and MSI’s X370 XPOWER Gaming Titanium are also compatible with AMD’s 16-core monster.

Not all boards with those chipsets will get support for the Ryzen 9 3950X. It’s up to the motherboard manufacturer to add support for the CPU via a firmware update. Only boards with robust power delivery systems are suited for the task, and you wouldn’t want to run this CPU on a motherboard with cheap power circuitry anyway.

If you’re shopping for a Core i9-9900K, your motherboard options will be similarly limited. The Core i9 processor can slot into any Intel 300-series motherboard, including B360, H310, H370, Z370, and Z390 chipsets. However, the power demands of the i9-9900K put a lot of stress on the motherboard VRMs, so you should not cheap out on your board selection, and you'll need a Z-series board for overclocking. A high-end Z390 is the best pairing for such a power-hungry processor.

Winner: Tie. Whether you opt for the Ryzen 9 3950X or the Core i9-9900K, you’ll want to opt for a high-end motherboard. These processors push the boundaries of modern CPUs and they should be complemented with an equally advanced motherboard.

Gaming Performance

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AMD’s Ryzen has always been an amazing foundation for productivity machines, but they’ve never been as competitive in gaming performance as they are now. AMD’s Zen 2 architecture offers significant improvements in per-core performance over previous generations, but the changes still can't completely counter Intel’s advantage.

Don’t get us wrong; the Ryzen 9 3950X can hold its own just fine in gaming workloads. In games like Civilization VI and Ashes of the Singularity: Escalation that can address all the cores of AMD’s mainstream workhorse, the Ryzen 9 3950X with PBO enabled is one of the best performers around. But in games like Far Cry 5 and Grand Theft Auto 5, the Ryzen 9 3950X runs head to head with processors that command a much lower price tag.

However, if what you’re after is the absolute highest frame rate in the games you play, there’s no other option than to go with Intel. What the Core i9 lacks in core count; it makes up with raw clock speed.

There’s little doubt that the Core i9-9900K remains the fastest gaming processor, but we’d be remiss to say that it is the best gaming processor. Intel’s own Core i7-9700K is a much better option for someone primarily interested in gaming because it offers roughly the same level of performance at a much lower price point.

Winner: Intel. Intel’s Core i9-9900K is faster at gaming than AMD’s Ryzen 9 3950X, but if gaming performance is what you’re after, you could save yourself quite a bit of money with an i7-9700K or Ryzen 7 3900X.

Productivity Performance

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If you’re in the market for a workstation PC for general productivity and Microsoft Office related tasks, you should probably be looking for a more mid-tier CPU to save some money. However, between the Ryzen 9 3950X and the Core i9-9900K, Intel’s processor outperforms AMD’s in several Microsoft Office applications. But the 2950X has a higher overall score due to its strength in Excel, where its extra cores and large caches help close the gap, and the Edge browser test.

For compilation tasks, like our timed-llvm test, the 3950X reigns supreme on the mainstream desktop.

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Rendering is where AMD’s Ryzen processors really shine. These tasks can often be split up across as many threads as available, which really allows the Ryzen 9 3950X to stretch its legs and show us what it can really do.

In the Cinebench R20 tests, our Ryzen 9 3950X was bested only by AMD’s 32-core Threadripper 2990WX and an overclocked 18-core Core i9-9980XE in the multi-threaded test. Intel’s Core i9-9900K @ 5.0 GHz managed to squeeze out 5,239 points, whereas the 3950X with PBO enabled cranked out nearly double that score with 9534 points. The 3950X even topped the single-core test with 545 points compared to 524 from the 9900K.

Our results from the POV-RAY multi-core test are just as damning for Intel. Where the Ryzen 9 3950X cranked out 7,955 points at stock settings, the Core i9 topped out at 3,566. The single-core test gave the Ryzen 508.7 points, and the i9 scored 421.4.

In Blender, the story continues: The Ryzen 9 3950X ran the quick benchmark in 505 seconds, while the i9 took its sweet time and finished the test in 916 seconds.

The LuxMark CPU test, Corona 1.3 Ray Tracing test, V-Ray CPU Test, and the NAMD molecular dynamics simulation test all netted similar results, with the Ryzen 9 clobbering the Core i9 by significant margins.

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AMD’s Ryzen 9 3950X is an excellent choice if you convert a lot of videos from one format to another. In our handbrake .MKV to MP4 x264 test, the Ryzen 9 outshined the Core i9-9900K by a very healthy margin. Our tuned Ryzen chip performed a task in 138 seconds that took our i9 216 seconds to complete.

Compression, Decompression, Encryption, and AVX instructions are all heavily multi-threaded tasks, which lend well to AMD’s high core count. Our Ryzen 9 left our Core i9 in the dust in every test except our single thread Geekbench and y-cruncher tests. When multiple threads are at play, these two processors are in completely different leagues.

Winner: AMD. Both chips have their strengths, but the Ryzen 9 3950X offers a more balanced performance profile. While the chip isn't as strong in some strictly lightly-threaded applications, none of the results represent a serious performance concern that would bar our recommendation. Pairing that more-than-acceptable performance in lightly-threaded workloads with the intense performance scalability in threaded productivity applications, where the 9900K frankly can't compete, and the win goes to the 3950X. 

Value Proposition

AMD’s Ryzen 9 3950X has a clear performance advantage over Intel’s Core i9-9900K in many use cases, but that doesn’t necessarily mean that it’s a better value for all users. The price difference between these two processors is quite significant, and worth some serious consideration.

If you’re primarily a gamer, then there’s no question: The i9 is a much better deal. Not only will you save a couple of hundred dollars; but you will also get better performance in most gameplay situations. 

Hobbyist creators that do video, audio, or 3D production will get better performance out of many applications if they go with the Ryzen, but they’ll still be paying a high price for that privilege that might not be worth it. Let’s be real: if you’re not making money off your work, waiting a few extra minutes for a render might not be a big concern. In those cases, you're better served by a Ryzen 9 3900X.

Professional creators, such as YouTubers, game designers, and podcast producers will see the benefits of spending the extra $250 to save time on their production pipelines for every project. When you look at the Ryzen 9 3950X through the prism of someone who wanted but couldn’t afford a Threadripper, the Ryzen 9 starts to look like a very attractive option.

Winner: AMD. Given the big price disparities between the chips, a lot of the value will boil down to what type of applications you use frequently. A 50% price premium for the 3950X is a lot to ask if you're a gamer or enthusiast, but for its target market, the Ryzen 9 3950X offers unprecedented value. You'll pay ~$23 per thread for the 3950X, which stands in stark contrast to the ~$61 per-thread asking price for the 9900K. Considering that the 3950X offers huge gains in threaded workloads for roughly a third of the cost-per-thread, that equates to a solid value proposition if you need that level of computing horsepower. It also offers more than acceptable performance in lightly-threaded applications and gaming. 

That said, most casual enthusiasts will be better served looking downstream to AMD's Ryzen 9 3900X for mainstream performance, while the Ryzen 9 3950X really is on a level of its own. 

Bottom Line

Given the pricing disparity between the two chips, this is a bit of an odd comparison, but the fact remains: We're comparing the best of the mainstream desktop from each company's arsenal, and AMD's Ryzen 9 3950X comes out ahead.

Intel is still the king for gamers looking for the highest gaming performance possible, and AMD continues to leverage the benefits of its core-heavy architecture. Intel's strengths remain in its speed in lightly-threaded workloads where its high core frequencies provide a tangible benefit, but there is a limit to its scalability in heavily-threaded applications. 

In contrast, the Ryzen 9 3950X offers a balanced performance profile with solid, but not always leading, performance in most lightly-threaded apps, but delivers an absolutely crushing amount of performance in threaded workloads. 

Ultimately, what we said about these processors during their reviews still stands true today: “Intel’s eight-core Core i9-9900K comes with everything to satisfy enthusiasts, like more cores, higher frequencies, and performance-boosting Solder TIM. Those improvements make the chip the fastest mainstream processor on the market, but the $500 asking price relegates it to the most extreme performance enthusiasts,” and “The Ryzen 9 3950X lets you jam highly threaded horsepower into an affordable motherboard, creating a new CPU class all its own. Its 16 cores and 32 threads redefine what's possible for the mainstream, and its comparatively affordable price-per-core is a great value.”