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The Intel Core i9-9900KS Special Edition Review: 5.0 GHz on All the Cores, All the Time

Intel's Core i9-9900KS arrives with impressive gaming performance.

(Image: © Intel)

Our Verdict

Intel's Core i9-9900K unlocks the ultimate in gaming performance, and the highly-binned chips also increase your chances of getting a highly-overclockable chip right out of the box. Just be prepared to pay a premium at retail for the limited-edition chip.

For

  • Gaming Performance
  • All-Core 5.0 GHz at stock settings
  • Overclocking headroom
  • Power consumption improvements
  • Compatible with 300-series motherboards
  • Solder TIM

Against

  • One-year warranty
  • Price
  • PCIe 3.0

Intel's Core i9-9900K sits atop the desktop PC gaming throne with leading performance in a wide range of games, allowing Intel to dominate the sliver of the ultra-high-end processor market where it remains uncontested in raw performance by AMD's competing Ryzen 3000 processors. 

Intel designed its new Core i9-9900KS Special Edition to take things one step further by taking the best silicon from its -9900K manufacturing line to create a new halo part specifically for gamers and streamers that boosts to 5.0 GHz on all cores. Surprisingly, Intel only assigns a $513-$524 recommended price for the chips, which is a relatively slim $25 premium over the standard -9900K models. 

Given the blistering-fast performance we found in our tests, that pricing would equate to a wonderful deal if you could find the chip at recommended levels, but we fully expect retailers to take advantage of the limited availability (the KS is only available until the end of the year) and charge a premium. 

For enthusiasts and gamers that don't want to deal with the hassles of overclocking, or for extreme overclockers looking for that last drop of performance, the Core i9-9900KS is unquestionably the new leader in gaming performance at both stock and overclocked settings. The gaming performance delta between the -9900KS and competing chips is often substantial enough that gaming enthusiasts looking for the absolute most performance, regardless of price, will seek out the processor. 

AMD isn't sitting 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. That chip isn't as fast at gaming as the Core i9-9900KS, but it does bring competitive gaming performance and much more threaded horsepower. 

Intel Core i9-9900KS Special Edition Specifications

ProcessSEP / RCP (USD)Cores / ThreadsTDP (Watts)Base Frequency (GHz)Total Cache (MB)PCIe LanesiGPUPrice Per Thread
Ryzen 9 3900X7nm$49912 / 24105W3.5 / 4.73224 Gen4No$20.79
Core i9-9900KS14nm$5138 / 16127W4.0 / 5.01616 Gen3Yes$32
Core i9-9900K14nm$4888 / 1695W3.6 / 5.01616 Gen3Yes$30.05
Ryzen 7 3800X7nm$3998 / 16105W3.9 / 4.53224 Gen4No$24.94
Core i9-9700K14nm$3748 / 895W3.6 / 4.91216 Gen3Yes$46.75
Ryzen 7 3700X7nm$3298 / 1665W3.6 / 4.43224 Gen4No$20.56

In short, the Core i9-9900KS is identical in nearly every fashion to the Core i9-9900K. The KS features the same 14nm++ process and Coffee Lake architecture as the standard Core i9-9900K, so it sports the same feature set, like dual-channel DDR4-2666 memory support and UHD 620 graphics. 

The -9900KS drops into existing 300-series motherboards after a BIOS update, but 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 beefy power circuitry.

Active CoresBase1 Core2 Cores3 Cores4 Cores5 Cores6 Cores7 Cores8 Cores
Core i9-9900KS (GHz)4.05.05.05.05.05.05.05.05.0
Core i9-9900K (GHz)3.65.05.04.84.84.74.74.74.7

Higher clock speeds are the Core i9-9900KS's real attraction. The -9900KS's premium silicon supports a 4 GHz base clock, which is a 400 MHz improvement over the -9900K that leads to a beastly 127W TDP rating. That's a big increase over the Core i9-9900K's 95W TDP. 

The -9900KS also delivers a 5 GHz Turbo Boost across all of its cores under any workload (AVX included), while the standard -9900K only boosts to 5 GHz on two cores. As expected of a higher-binned processor, Intel's Core i9-9900KS should overclock higher than garden-variety -9900K chips, but the silicon lottery still applies (your mileage may vary). The higher quality silicon also affords tremendous power consumption advantages, which we'll cover shortly. 

Like the Core i9-9900K before it, the -9900KS comes with Intel's translucent plastic dodecahedron packaging, doesn't come with a bundled cooler, and features solder TIM (sTIM) to facilitate efficient thermal transfer from the die to the heatspreader. That helps with overclocking, which is fully enabled through the -9900KS's unlocked ratio multiplier. 

Like all ninth-gen chips, the -9900KS supports Intel's free and simple-to-use Performance Optimizer (IPM) software tool that automatically tunes and overclocks your processor. As with all of Intel's processors, overclocking voids your warranty unless you purchase a separate Performance Tuning Protection Plan that covers damage due to overclocking. 

Surprisingly, Intel's standard warranty only covers the Core i9-9900KS for one year, which stands in contrast to the standard three-year warranty period for the company's other desktop processors. Intel chalks this shorter warranty period up to 'limited availability,' but its 40th-anniversary Core i7-8086K also sold in limited quantities and carried a three-year warranty. Intel is transparent about the shorter warranty period, but you should take it into account. 

Core i9-9900KS Boost Frequency and Thermals - 5 GHz, all the Time

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(Image credit: Future)
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(Image credit: Future)
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(Image credit: Future)

We turned the same amount of attention to the KS's 5.0 GHz boost as we have with our series of AMD Ryzen 3000 boost clock tests. We put the chip through the wringer in a variety of workloads with different cooling solutions and found that, given adequate cooling, the chip sustains 5.0 GHz on all cores at stock settings, regardless of instruction type (AVX workloads included). 

As outlined in the charts above, we stress-tested the chip with both a beefy custom watercooling loop with two 360mm radiators, and a Corsair H115i AIO watercooler. Both cooling solutions facilitated a consistent 5.024 GHz clock rate, but air cooling doesn't seem to be a viable option. We paired the chip with a beefy Noctua NH-D15S air cooler, and at stock settings, the chip often bumped against its 100C thermal limit, which triggered clock throttling to protect the processor. Contrary to some reports, the Core i9-9900KS will obviously not support overclocking with an air cooler.

Intel's official spec sheet lists a 130W cooler as the entry-level solution. That fits well with the Core i9-9900KS's 127W TDP, but Intel defines the TDP at base frequencies (PL1 - Power Level 1), and that value represents the amount of power the chip dissipates under load, not actual power consumption.

However, Intel's chips shift into Power Level 2 (PL2) during boost activity, which the company defines as 25% over TDP (158.7 Watts for the KS) for a boost duration (Tau) of 28 seconds. Motherboard vendors often ignore boost duration limits, as we see with our own tests above, so you can expect very aggressive boost activity with most motherboards. Performance will vary based upon each motherboard vendors' policy, but the parameters are configurable. Even with Solder TIM, thermal density presents challenges. If you plan on tuning, open- or closed-loop liquid cooling is a must. Even then, the thermal output could limit your overclock

Core i9-9900KS Special Edition Binning

Every processor die is unique, even when harvested from the same wafer. Intel tests the individual dies from each wafer in a binning process to find the best and worst silicon, first sorting out die with defects for use in models that have fewer cores or deactivated graphics units. In some cases, dies are discarded altogether.

Even after the initial sorting, some die can deliver higher frequencies at a lower voltage than others, while most die require more voltage (which generates more heat) to deliver the same level of performance. Intel assigns each tier of chips into separate bins that dictate if the chip will find its way into downstream models that have lower frequency requirements, or if the chip will be reserved for high-end models, like the Core i9-9900K.

But like all chip manufacturers, even Intel's fully-functional halo parts have some wiggle room in the specifications to account for silicon variation, meaning the chips are programmed for the lowest common denominator of the bin. That leaves some chips that fall on the high end of the binning bell curve, or "thin bin" parts in Intel parlance, that find their way into the hands of lucky owners who win the silicon lottery.

Intel's Core i9-9900KS represents the cream of its silicon crop. Intel says these rare chips offer what we would typically expect from an overclocked system, but at stock settings. Let's see how that looks throughout our test suite.


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  • Aspiring techie
    If my memory serves me correctly, the Stockfish chess engine got stomped by Google's Deepmind AlphaZero, not the other way around.
    Reply
  • atavax
    Why isn't one of the Cons the security vulnerabilities in modern Intel CPUs?
    Reply
  • joeblowsmynose
    I just watched Steve Burkes review, and he notes some pretty interesting caveats with this chip ...

    The title of this article: "5.0 GHz on All the Cores, All the Time" --- is not true if it is used with a motherboard manufacturer that stuck to Intel's TDP guidelines, like Asus did.

    On Asus boards, this chip only boosts all core @5ghz for a limited time then drops back down to maintain reasonable power consumption, as per Intel's own TDP specification for this processor. So basically, Intel gave mobo makers specs to keep TDP ~127w but really it was just their way of lying about TDP but deferring that misinfo to the mobo makers. The mobo maker that actually chose not to allow a misleading TDP now gets punished ... sounds like an Intel move.

    So I assume this will mean that Asus is going to be pissed with Intel since gigabyte and MSI boards will let it suck all the power it needs to maintain 5ghz -- completely disregarding the TDP is the only way it boosts at 5ghz all cores, full time.

    So how this chip performs has far more to do with the mother board, than the chip. This is stupid.


    As an aside question ... what's the cooling power required for OCing? The OC testing here was done using 720mms worth of radiators on a custom loop - what's next ... LN2 testing? ;) We know the limit is somewhere between the H115i and the dual rad custom loop, but I wonder where that is. A lot of cooling for any OCing anyway it seems ... (but expected).
    Reply
  • colson79
    I find it sort of annoying how all these reviews always talk about how much better gaming performance is on Intel but leave out the fact that that is only 1080P or lower. The push Intel like it's the only choice for gamers without mentioning the fact that almost every game has the same performance with resolutions over 1080P. I haven't gamed on a 1080 P resolution for years. I think a lot of less informed people completely skip AMD as an option because these review sites push the Intel 1080 P benchmarks so hard. At a minimum I think they should include the 2k and 4k benchmarks in their CPU reviews.
    Reply
  • PCWarrior
    joeblowsmynose said:
    I just watched Steve Burkes review, and he notes some pretty interesting caveats with this chip ...On Asus boards, this chip only boosts all core @5ghz for a limited time then drops back down to maintain reasonable power consumption, as per Intel's own TDP specification for this processor.
    If "Out of the box" was literally meant to mean “no bios fiddling whatsoever” then stock behaviour should also be with the XMP profile disabled as you need to get into the bios in order to enable it. And for ASUS boards, the moment you go to enable XMP, it prompts you to load optimised defaults which removes power limits. Also it should be pointed out that no-power-limits and MCE are not the same thing and are not viewed as the same thing by Intel. Reviewers like Steve Burkes from Gamers Nexus and Der8auer seem to conflate the two. They are NOT the same. No-power-limits sticks to stock turbo frequency tables (for example the regular 9900K still only boosts to the stock all-core turbo of 4.7 GHZ but instead for only 25 seconds it does so indefinitely). MCE, on the other hand, means both no-power-limits AND to make the all-core turbo boost equal to the single-core turbo boost (for example for the regular 9900K with MCE enabled it means boosting to 5GHZ on all cores indefinitely). For warranty purposes MCE is considered an overclock by Intel. No-power-limits is NOT considered an overclock by Intel. It is stock and it is left to the motherboard vendor how the settings are configured out of the box.
    Reply
  • PCWarrior
    colson79 said:
    I find it sort of annoying how all these reviews always talk about how much better gaming performance is on Intel but leave out the fact that that is only 1080P or lower.
    They use 1080p because this is currently the highest resolution where with a top GPU there is definitely a cpu bottleneck and it is therefore a cpu test. It is not a cpu test when there is a gpu bottleneck. With current gpus, even with the likes of 2080Ti, you can have an i3 8100 and still do as well in 4K gaming as with a 9900K. However fast forward to the future and using something like a 3080Ti or a 4080Ti and you will be having a cpu bottleneck across all games at 1440p and probably even at 4K. With a 3080Ti or a 4080Ti you will be getting the same fps that you currently get with a 2080Ti at 1080p but at 1440p and 4K. You can verify this by going backwards to a lower resolution. If you have a 2080Ti, you get the same fps for 720p and 1080p because in a cpu bottleneck situation fps can only increase with a better cpu, not a better gpu.
    Reply
  • joeblowsmynose
    PCWarrior said:
    If "Out of the box" was literally meant to mean “no bios fiddling whatsoever” then stock behaviour should also be with the XMP profile disabled as you need to get into the bios in order to enable it. And for ASUS boards, the moment you go to enable XMP, it prompts you to load optimised defaults which removes power limits. Also it should be pointed out that no-power-limits and MCE are not the same thing and are not viewed as the same thing by Intel. Reviewers like Steve Burkes from Gamers Nexus and Der8auer seem to conflate the two. They are NOT the same. No-power-limits sticks to stock turbo frequency tables (for example the regular 9900K still only boosts to the stock all-core turbo of 4.7 GHZ but instead for only 25 seconds it does so indefinitely). MCE, on the other hand, means both no-power-limits AND to make the all-core turbo boost equal to the single-core turbo boost (for example for the regular 9900K with MCE enabled it means boosting to 5GHZ on all cores indefinitely). For warranty purposes MCE is considered an overclock by Intel. No-power-limits is NOT considered an overclock by Intel. It is stock and it is left to the motherboard vendor how the settings are configured out of the box.

    A complicated way to lie about TDP ... lol. Whatever you say, it disingenuous.
    Reply
  • TJ Hooker
    joeblowsmynose said:
    On Asus boards, this chip only boosts all core @5ghz for a limited time then drops back down to maintain reasonable power consumption, as per Intel's own TDP specification for this processor. So basically, Intel gave mobo makers specs to keep TDP ~127w but really it was just their way of lying about TDP but deferring that misinfo to the mobo makers. The mobo maker that actually chose not to allow a misleading TDP now gets punished ... sounds like an Intel move.
    FYI this applies to all Intel CPUs with turbo boost, not just the 9900KS. Officially they're all supposed to have a limited duration boost buy nearly all mobos remove this limit. And they've been doing so for some time, so it seems Intel doesn't really care.

    Which makes sense, as it improves their benchmark scores and if anyone complains about power draw they can just point to their states rules for power levels and blame the mobo manufacturers, even though they've implicitly given them permission to do this by allowing it to go on in a widespread fashion.
    Reply
  • TJ Hooker
    Last page:
    Bear in mind that we tested with an Nvidia GeForce GTX 1080 at 1920x1080 to alleviate graphics-imposed bottlenecks.
    Should say 2080 Ti.
    Reply
  • Soaptrail
    PCWarrior said:
    They use 1080p because this is currently the highest resolution where with a top GPU there is definitely a cpu bottleneck and it is therefore a cpu test. It is not a cpu test when there is a gpu bottleneck. With current gpus, even with the likes of 2080Ti, you can have an i3 8100 and still do as well in 4K gaming as with a 9900K. However fast forward to the future and using something like a 3080Ti or a 4080Ti and you will be having a cpu bottleneck across all games at 1440p and probably even at 4K. With a 3080Ti or a 4080Ti you will be getting the same fps that you currently get with a 2080Ti at 1080p but at 1440p and 4K. You can verify this by going backwards to a lower resolution. If you have a 2080Ti, you get the same fps for 720p and 1080p because in a cpu bottleneck situation fps can only increase with a better cpu, not a better gpu.

    Yes but they should include a couple 1440p and 4K resolution benchmarks to put context. It could still be beneficial to buyers to get the cheaper options like the AMD Ryzen 3600 and upgrade in a couple years than buy the 9900KS and stick with it for 6 years.
    Reply