Intel Core i9-10900K Review: Ten Cores, 5.3 GHz, and Excessive Power Draw

Intel dialed up the power for its new halo $488 Comet Lake-S Core i9-10900K, quite literally, to bulk up its mainstream desktop flagship with two extra cores for a total of ten cores and 20 threads. Aside from the promise of world-leading gaming performance, Intel also lowered gen-on-gen pricing to help fend off AMD's Ryzen processors that currently hold sway over our list of best gaming processors and dominate our CPU Benchmark Hierarchy. 

Once again, Intel aims its flagship chip squarely at enthusiasts and power users, touting the Core i9-10900K as the fastest gaming processor in the world. That performance comes mostly via the processor's extra cores and the fact that it basically comes pre-overclocked to an all-core 4.9 GHz, not to mention the peak 5.3 GHz speeds.  

Intel's Core i9-10900K still doesn't match AMD's halo 16-core 32-thread Ryzen 9 3950X in terms of threaded performance. Instead, the 10900K competes with the 12-core 24-thread Ryzen 9 3900X in terms of both performance and price, but Intel's chip has the highest power consumption we've seen recently on the mainstream desktop. Intel pushes the 10900K's TDP envelope up to 125W (a 30W gen-on-gen increase), but that's only a measure of base power consumption. Intel rates the processor for 250W at peak performance, and we even measured peaks as high as 325W at out-of-the-box settings. Naturally, that results in a lot of heat. 

Intel does have a few tricks to deal with the resulting heat and improve overclocking, like thinning the die and using a thicker heat spreader, but cooling is still a significant challenge. The 10900K's high power consumption even overwhelmed our 280mm watercooler during some tasks, so you'll need a brawny cooler to handle the increased heat output. 

Intel also added a few new features to its halo product to satiate enthusiasts, like per-core hyper-threading adjustments and reworked overclocking software, among other new tunable knobs. However, because the Core i9-10900K is basically an overclocked processor right out of the box, there is precious little overclocking headroom with conventional cooling.

However, provided you have adequate cooling, the Core i9-10900K is unquestionably the fastest gaming processor on the market. It also offers incredibly snappy performance in lightly-threaded apps, and solid performance in heavily-threaded workloads. Despite its insatiable power consumption and high heat output, the 10900K will be sure to find some uptake from performance enthusiasts that are prepared to splurge on a robust motherboard, power supply, and cooler, but most users would be better served with cheaper AMD alternatives, like the Ryzen 9 3900X. 

Intel Comet Lake-S Core Specifications and Pricing

The Comet Lake-S lineup shores up the Core family with more cores or threads at every price point that equate to deep price cuts, which we recently covered in depth. Intel reduced its gen-on-gen Core i9 pricing by 20% per core and cut pricing up to 50% per thread on other downstream models. For the downstream models, Intel finally enables hyper-threading on its Core i7, i5, and i3 lineups. That creates some surprisingly strong value plays in the mid-range, at least on paper. 

For the Core i9-10900K, Intel essentially stretched out its existing 14nm++ die and the Skylake architecture's ring bus interconnect. The integrated UHD Graphics 630 engine remains unchanged and is available on all models, but you also have the option to buy graphics-less F-series variants to save some cash (you can shave off $16 the Core i9-10900KF). 

Intel Core i9-10900K Specifications and Pricing

The real story comes in the form of higher clock rates, extra cores, more performance, and all of the power consumption pain that entails. Intel has brought support for its Turbo Boost Max 3.0 technology from the high end desktop to its mainstream platforms, and also roped in its Thermal Velocity Boost (TVB) mechanism from its mobile chips. This creates a multi-tiered boost implementation that can be incredibly confusing, so here is a short summation of each boost and what it entails:

• Turbo Boost 2.0: Increased frequency if chip operates below power, current, and temperature specifications.
• Turbo Boost Max 3.0: Fastest cores are identified during binning, then the Windows scheduler targets the fastest two active cores (favored cores) with lightly-threaded applications. Chip must be below power, current, and temperature specifications.
• Single-Core Thermal Velocity Boost: Fastest active favored core can boost higher than Turbo Boost Max 3.0 if below a pre-defined temperature threshold (70C) and all other factors adhere to TB 3.0 conditions. 
• All-Core Thermal Velocity Boost: Increases all-core frequency when all cores are active and the chip is under 70C. 

The Core i9-10900K's ten cores and 20 threads operate at a 3.7 GHz base frequency when all cores are loaded, but that can improve to 4.8 GHz via the normal Turbo Boost, and up to 4.9 GHz via Intel's Thermal Velocity Boost (TVB) feature. TVB is yet another layer to Intel's boost mechanism, but according to Intel, it only engages if the processor remains below 70C. However, we found that the all-core TVB frequency routinely engages regardless of chip temperature, which means motherboard vendors are still free to largely ignore Intel's power recommendations (functionality will vary by board). These vastly improved all-core boosts give the 10-core 10900K a fighting chance to match the 3900X's twelve cores in threaded applications, but as we'll see, that comes with a heavy power burden. 

TVB also applies to single-core boosts, too. Intel touts a 5.3 GHz single-core boost if the chip remains under 70C and meets all of the other normal requirements for boost activity. The chip downshifts to a dual-core 5.2 GHz via Turbo Boost Max 3.0 if the workload spreads across two cores, and then falls to 5.1 GHz if the workload lands in a single 'normal' core. Intel's goal is to provide the utmost in single-core performance, which remains its key advantage against AMD's Ryzen processors in lightly-threaded tasks like gaming and standard desktop PC applications.

All of this means that, given appropriate cooling and power delivery, you can hit 5.3 GHz in lightly-threaded work and up to 4.9 GHz in demanding all-core workloads. Intel assigned the 10900K a 125W TDP envelope, but that only applies when the chip operates at its base frequency - remember, Intel doesn't guarantee that you'll ever see Turbo Boost frequencies during normal operation. The chip is free to jump to 250W during boost activity, and motherboard vendors can ignore those limits.

Unlike the competing Ryzen 9 3900X, the Core i9-1900K doesn't come with a cooler, but at least the requisite motherboards are compatible with existing 115x coolers. Surprisingly, Intel only recommends a cooler that meets the PCG 2015D specification, meaning a cheap cooler that comes as either a 120mm AIO or a standard heat sink and fan, both of which can only dissipate 130W of waste heat. While this may technically meet Intel's specification for the base TDP rating, you would likely would see little to no Turbo Boost activity with a cooler of that class. 

We tested with the beefier Noctua NH-D15 and could mostly satisfy cooling requirements in standard desktop PC applications, but you will lose out on performance in workloads that push the boundaries with AVX instructions. As such, you'll need a greater-than-280mm AIO cooler or a custom loop to unlock the best of the 10900K. You'll also need an enthusiast-class motherboard with beefy power circuitry, and also plan on some form of active cooling for the motherboard's power delivery subsystem. 

Intel's Core i9-10900K comes with a few other tweaks, like improved memory support that jumps from DDR4-2666 to DDR4-2933, but still lags AMD's standard DDR4-3200 support. Intel also increased the L3 cache to 20MB. As before, Intel supports the PCIe 3.0 interface, while AMD has long since moved on to PCIe 4.0 and its doubled bandwidth. 

You'll need to upgrade to an LGA1200 motherboard for the new Comet Lake chips, and many Z490 models do support the PCIe 4.0 interface, albeit at the cost of increased pricing. However, that feature exists for as-yet-officially-unnamed future chips (read; Rocket Lake), so you'll pay extra for flagship motherboards that come with a feature you won't be able to use unless you upgrade your processor in the future.   

We also see generally higher pricing due to the bulky power delivery subsystems needed to feed Comet Lake with enough clean current. AMD's X570 platform is also pricey, but you can opt to use older, more cost-conscious X470 motherboards instead. You don't have the option of using older motherboards with Intel's lineup, and B-series and H-series boards haven't arrived yet, so you'll have to budget in a new board. We covered the Z490 motherboard ecosystem in more detail in our accompanying article.