Intel Core i9-9900K 9th Gen CPU Review: Fastest Gaming Processor Ever

Editor's Choice

Tom's Hardware Verdict

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.


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    Gaming performance

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    Performance in both single- and multi-threaded workloads

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    Solder TIM


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    Cooling requirements

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    Power consumption under heavy load

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Intel Strikes Back

Although Intel added more cores to its previous-gen Coffee Lake processors in an effort to keep up with AMD's Ryzen CPUs, struggles with its 10nm node obviously delayed a more significant response. The company's ninth-generation Core processors, otherwise known as the Coffee Lake refresh, represent another step forward in a contentious battle for desktop supremacy as the company looks to maintain its top spots on our list of Best CPUs

Intel's line-up matches AMD's Ryzen core-for-core, including a new Core i9 with eight Hyper-Threaded cores (8C/16T) and the highest frequencies we've seen in the mainstream space. There's also a bulked-up Core i7 armed with two extra cores, plus a revamped Core i5. AMD isn't setting still though: The company recently released its own new flagship, the 16-core 32-thread Ryzen 9 3950X, to fend off Intel's new challengers.

AMD's high core counts, aggressive prices, and nods to enthusiasts have earned it plenty of goodwill. Now it's Intel's turn to respond. The Core i9-9900K, for instance, ships in a a translucent plastic dodecahedron obviously meant to wow system builders, similar to the way AMD impressed with its Threadripper packaging. Intel also switched back to using Solder Thermal Interface Material (STIM) between the die and heat spreader, facilitating better thermal transfer to cope with more cores and higher overclocks. Ninth-gen Core CPUs are also Intel's first with hardware-based mitigations for the Meltdown and Foreshadow vulnerabilities. These should minimize the performance impact of circumventing recently discovered exploits.

Core i9-9900K is the fastest mainstream desktop processor we've ever tested. But it's also one of the most expensive. Knowing that Intel does not match AMD's value proposition, is the ultimate in desktop performance worth paying extra for? The new Core i9 was incredibly impressive through our benchmark suite. However, most users would be better served by cheaper alternatives, such as Core i7-9700K.

Then again, if money is no object and you have the need for speed, Core i9-9900K is the CPU to buy.

Intel Core i9-9900K

The Coffee Lake refresh begins with three new K-series processors. They all feature the same underlying Coffee Lake microarchitecture as previous-gen models. And as expected, the Core i5 and Core i7 brands are represented. This time around, though, an eight-core, 16-thread Core i9 commands the spotlight.

The new K-series chips are manufactured on Intel's 14nm++ node, include an integrated UHD 630 graphics engine, sport unlocked ratio multipliers that enable easy overclocking, and boast support for dual-channel DDR4-2666 memory. Intel also responds to increasing RAM density by doubling memory capacity support up to 128GB.

Swipe to scroll horizontally
Row 0 - Cell 0 Core i9-9900KCore i7-9700KCore i5-9600K
ArchitectureCoffee LakeCoffee LakeCoffee Lake
Cores / Threads8 / 168 / 86 / 6
Base Frequency (GHz)
Boost Frequency ( Active Cores - GHz)1-2 Cores - 5.04 Cores - 4.8 8 Cores - 4.71 Core - 4.92 Core 4.8 4 Core 4.78 Core 4.61 Core - 4.62 Core - 4.54 Core 4.46 Core 4.3
L3 Cache16MB12MB9MB
Memory SpeedDDR4-2666DDR4-2666DDR4-2666
Memory ControllerDual-ChannelDual-ChannelDual-Channel
PCIe Lanesx16x16x16
Integrated UHD Graphics GT2 (Base/Boost MHz)350 / 1200350 / 1200350 / 1150
Recommended Customer Pricing$488 - $499$374 - $385$262 - $263

Core i9-9900K's Solder TIM improves the thermal transfer efficiency between the die and heat spreader, facilitating the headroom needed for two more physical cores on the Core i9 and i7 models without violating a 95W envelope at base clock rates. What's more, the -9900K's base frequency is 3.6 GHz, just 100 MHz lower than the previous-gen Core i7-8700K. And that's after adding those two extra cores.

The STIM, which is applied inside all three new models, also improves overclockability. Enthusiasts who previously lauded AMD for using Solder TIM in its Ryzen processors should be happy with Intel's decision here.

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Row 0 - Cell 0 Base1 Core2 Cores3 Cores4 Cores5 Cores6 Cores7 Cores8 Cores
Core i9-9900K (GHz)
Core i7-9700K (GHz)
Core i7-8700K (GHz)
Core i7-8086K (GHz)
Core i5-9600K (GHz) -
Core i5-8600K (GHz)

Improved heat dissipation also facilitates impressive clock rates across the ninth-gen models. Core i9-9900K stretches up to 5.0 GHz when two cores are active, outstripping the Core i7-8086K and its ability to hit 5.0 GHz on one core. As you can see in the chart above, Intel is pushing the voltage/frequency curve with its eight-core models. They both feature much higher boost multipliers than previous-gen CPUs. These should help extend Intel's advantage in lightly-threaded tasks like gaming. Meanwhile, the extra cores help Intel compete readily against Ryzen in more taxing workloads.

Core i7-7820X is perhaps the most comparable CPU from Intel's high-end desktop portfolio. But it employs a fundamentally different design. The $600 chip requires an expensive X299 motherboard, is best paired to a quad-channel memory kit, lacks integrated graphics, and utilizes a mesh architecture for connecting on-die logic instead of the familiar ring bus (check out our deep dive for more information). As we've shown, the mesh architecture has a negative impact on some desktop-class workloads, so it isn't the best solution for enthusiasts.

As expected, the -9900K's extra cores are accompanied by two additional 2MB slices of L3 cache, adding up to 16MB across the processor. The Core i7-9700K comes with the same 12MB of L3 cache as its predecessor. Given a higher core count, though, this actually represents a lower cache-per-core ratio, meaning Intel purposely disabled some of the -9700K's cache for the purpose of segmentation.

Intel's Core i7 series traditionally features Hyper-Threading, allowing one physical core to execute two software threads simultaneously, thus boosting performance. Kaby Lake-based processors included up to four cores and eight threads, while Coffee Lake offered as many as six cores and 12 threads on the highest-end models. The 95W Core i7-9700K breaks this tradition with eight cores and no HT support. If you assume that HT yields a 15-20 percent performance uptick under ideal conditions, then Intel's clever removal of the feature on its $374 Core i7-9700K should make the 8C/8T CPU faster than the 12-threaded Core i7-8700K in most workloads, maintaining the carefully manicured product stack.

Ninth-gen Core i5s still come with six cores and no Hyper-Threading, just like the Coffee Lake generation before them. The 95W Core i5-9600K ($265) operates at a 3.7 GHz base clock rate that boosts as high as 4.6 GHz. Intel pairs each core with a 1.5MB of L3 cache, adding up to 9MB.

Swipe to scroll horizontally
ModelCores / ThreadsBase FrequencyBoost FrequencyMemory SupportPCIe LanesCacheTDPPrice
Core i9-9900K8 / 163.6 GHz5 GHz (1 / 2 Core)4.8 GHz (4 Core)4.7 GHz (6 / 8 Core)DDR4-26661616MB95W$488
Ryzen 7 2700X8 / 163.7 GHz4.3 GHzDDR4-296616 + 4 (NVMe)16MB105W$329
Core i7-9700K8 / 83.6 GHz4.9 GHz (1 Core)4.8 GHz (2 Core)4.7 GHz (4 Core)4.6 GHz (6 / 8 Core)DDR4-26661612MB95W$374
Core i7-8086K6 / 124.0 GHz5.0 GHzDDR4-26661612MB95W$425
Core i7-8700K6 / 123.7 GHz4.7 GHzDDR4-26661612MB95W$330
Ryzen 7 27008 / 163.2 GHz4.1 GHzDDR4-296616 + 4 (NVMe)16MB95W$229
Core i5-9600K6 / 63.7 GHz4.6 GHz (1 Core)4.5 GHz (2 Core)4.4 GHz (4 Core)4.3 GHz (6 Core)DDR4-2666169MB95W$262
Core i5-8600K6 / 63.6 GHz4.3 GHzDDR4-2966169MB95W$279
Ryzen 5 2600X6 / 123.6 GHz4.2 GHzDDR4-296616 + 4 (NVMe)16MB65W$229
Ryzen 5 26006 / 123.4 GHz3.9 GHzDDR4-296616 + 4 (NVMe)16MB65W$199

The new Core CPUs drop into existing 300-series motherboards after a BIOS update, though Intel's partners also have a slew of Z390 motherboards available, which you can see here. As we'll illustrate, the Core i9-9900K, specifically, draws enough power to make VRM selection an important factor in your motherboard purchase, especially if you plan on overclocking. Luckily, most high-end Z390 motherboards already employ beefier power circuitry than the Z370 models.

Plan on buying a beefy cooler for the Core i9-9900K, too. Its eight-core die hides beneath the same heat spreader used on previous-gen six-core models, meaning that even with Solder TIM, thermal density presents challenges. Intel's official spec sheet lists a 130W cooler as the entry-level solution. If you plan on tuning, open- or closed-loop liquid cooling is a must. Even then, thermal output could be what limits your overclock.

Let's see how the Core i9-9900K and its stablemates perform in our test suite.

Update 10/22: Corrected the recommended pricing for the Ryzen 7 2700X in our efficiency charts. 


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  • dlim389
    "The better the cooling, the better power consumption"? What?! This doesn't make sense at all. You meant the better the cooling, the lower the temperature.
  • siman0
    "Redefine" at double the price of a 2700x it needs to do more than that. The price diffrence is more than enough to go up another GPU tier ie 1070ti to a 1080ti. Id rather have more pcie bandwidth and the ability to upgrade my cpu till 2020. The only way Id recommend a upgrade to something close is if you already have the motherboard. But even then Id say the 9700k.
  • s1mon7
    Wait, so it performs within a spitting distance of the 2700x with DOUBLE the power consumption and price? Holy smokes, I thought Intel will be able to easily take on AMD after they launch their 8-cores. I have to say that these results were very surprising to me, since I believed in this being the ace up Intel's sleeve. This is really interesting, and a big win for AMD. The 9900K goes through twice the power just to squeeze out that extra clock speed edge to outperform the 2700x by a mere 10%, at double the price, mind you.

    Intel clearly needs 10nm and a new architecture to go back into the game. As is, I struggle to think of any reason to buy the 9900k.
  • TCA_ChinChin
    Interesting chip from Intel, but if you are looking at CPUs from a performance per dollar point of view, its rather disappointing. The real disappointment is the 9700k which is more expensive than the 8700k but performs basically the same on average.
  • Adrian Ocampo
    As a gamer, why would I buy a 9700K when an 8700K trades blows with the 9900K in both gaming and productivity. It just doesn't make sense. Its like its just competing with its own product as this point. I would be better off buying an 8700K deliding it, put liquid metal and overclock to 5.0Ghz for a much lower price than a 9900K.
  • gfaiii
    Guys just as a heads up you should say second generation 1151 socket, these are NOT compatible with 200 series boards that have 1151 sockets (without modding)
  • sonichedgehog360
    Ladies and gentlemen, Intel’s FX 9000 series.

    (By the way, I totally saw this coming what with the crazy clock speeds they were pushing.)
  • Johnpombrio
    I was surprised on how well the i9-9900K did on stock clocks. I may not even bother with overclocking as it does well even without it and I may be able to use air cooling that way. Compared to my Kaby Lake i7-7700K, it definitely is a big step up. I already have the ASUS Strix Z380 mobo, 32GB Corsair Dominator Platinum memory kit and have preordered the CPU.
  • sstanic
    how is this an editor's choice is beyond me. but not beyond marketing people, is it?
  • redgarl
    For the money, you can buy a motherboard, a CPU and a 1080 GTX for the same price as the 9900k with it's motherboard.

    Also, you tested this system on a 600$ motherboard... 600$ and a prenium cooling solution.

    This system is above the 2000$ threshold compared to an AMD one barely hitting the 1000$.