Intel Core i9-10900K review: For a top-end gaming build

A couple of weeks ago, I reviewed Intel's new Core i5-10600K CPU, and while the company had sent me both the i5 and the Core i9-10900K, I wasn't quite ready for the i9 review. As I mentioned at the time, it was my first CPU review and my first PC build, and I realized quickly that some of the parts that worked great on the Core i5 just didn't cut it for the Core i9.

That's also why the Core i5 works so well for mainstream gaming performance. It's relatively inexpensive, and you can use relatively inexpensive parts in your build. With the Core i9, I found I needed a better CPU cooler and a more powerful PSU. I'm going to show benchmarks from my first build, which should make it easy to compare to the i5, as well as from the jacked up build, which also has an upgraded GPU and more RAM.

Parts

Build one

The original plan was to simply swap the CPU, but I after playing games for a couple of hours, the PC would start making a whining noise and then just randomly shut down. There wasn't even a blue screen. When I did see a blue screen was when running some benchmarks and the CPU got too hot.

So I went and got some new parts. As I noted in my Core i5 review, parts are hard to come by these days, which is why it took me so long to write this. Stores are closed, shipments are delayed from online orders, and so on.

Build two

As you can see, the parts I needed for the second build were more expensive, and I also jacked up the GPU and the RAM. There's no thermal compound listed, since the Noctua U12A came with Noctua's own.

Swapping out the CPU cooler and the PSU made a huge difference. There was no more overheating, and in fact, I had to work hard to even get the Core i9-10900K to run hot. The U12A is a phenomenal cooler. With the Intel cooler, it idled at around 52 degrees Celsius, but with the Noctua, it was consistently under 40 degrees.

As for the power supply, the 650W unit only had issues when I tried to push the CPU hard. This is a 125W CPU, and even with all of the parts running at their normal wattage, 650W is enough. But as things draw more power, it's not enough.

Also, I just want to remind you that Intel's Comet Lake S CPUs do require a new motherboard, one that has the LGA 1200 socket. I had a fun time finding compatible parts for a motherboard that wasn't out yet, but while the CPU does require the new socket, the CPU cooler does not. Any LGA 115x cooler will fit on LGA 1200.

Core i9-10900K Specs

You can get the full list of specs here.

The biggest thing missing, just like with the Core i5, is PCIe 4 support. That's one thing that AMD's latest Ryzen processors have that Intel does not. PCIe 4.0 gets you a 16GT/s bit rate and 64GB/s total bandwidth, doubling its predecessor. This is something to keep in mind, because Comet Lake S does require a newer LGA 1200 motherboard.

Intel's 11th-gen CPUs will still use the LGA 1200 socket, so you could reasonably swap out this generation's CPU with the next one. However, a board you buy today probably doesn't have PCIe 4.0, so you might end up wanting a new one anyway.

Note that while the CPU does support DDR-2933, I still only used DDR4-2666 memory, frankly, because that's what I had. Also, DDR-2666 is what the Core i5 supports, so the memory options is definitely one of the improvements in the Core i9; it's just not one that I was able to take advantage of for this review.

Performance

Performance with the Core i9-10900K is a dream. Immediately after switching to the newer CPU, even with the original build, I could feel the difference. Boot time was reduced drastically, apps load faster, and so on. I can easily and comfortable say that simply, everything is faster than with the Core i5-10600K. And why shouldn't it be? The Core i9 costs nearly twice as much.

With the Core i9-10900K, the 'K' means that it's unlocked for overclocking, so that means that you can push it even further than it goes by default. One thing that you'll find different between building your own and buying a Core i9-10900K PC, however, is that a prebuilt PC will likely have an OEM utility for easy overclocking, while if you build your own, you'll either have to find your own utility, or use the BIOS.

That's not all it means though, because the Core i9-10900K is actually more powerful by default than the Core i9-10900. Intel's new K-series processors now have a 125W TDP, up from the previous generation's 95W. Meanwhile, the regular locked processors are still at 65W. The 3.7GHz base clock speed is more than the locked Core i9's 2.8GHz as well.

The other big performance boost with this generation is once again, that it has more cores. The Core i9-10900K has 10 cores and 20 threads, a record for an S-series processor from Intel. Naturally, this provides a boost when it comes to workloads that can take advantage of multiple threads. Last year's model had eight threads, and it was only seventh-generation Kaby Lake a few short years ago when the very best Intel was putting out was a quad-core desktop CPU.

I ran the Core i9-10900K with an Nvidia GeForce RTX 2080 and 32GB HyperX Fury DDR4-2666 RAM on the first build, and with an Nvidia GeForce RTX 2080 Ti and 64GB HyperX Fury DDR4-2666 RAM on the second. The main point that I want to get across is that performance was phenomenal, from productivity to video editing to gaming.

I used a variety of tools for benchmarks, and I'm going to show results from both build one and build two.

CPU-Z

CPU-Z is an application that can be installed through ASUS' Armoury Crate application. Armoury Crate is also where you can find driver updates for components on the motherboard and such. CPU-Z can show you various information for your system, and you can run benchmarks that can easily be compared to competing processors from AMD or alternatives from Intel.

Gallery: Core i9-10900K CPU-Z 1

Gallery: Core i9-10900K CPU-Z 2

Someone pointed out to me that I made the mistake of using single-channel memory with the first build. That's not an issue with the second one, especially since all four slots are filled.

Right out of the gate, the Core i9-10900K smokes the Core i9-7980XE in single-core, and it beats the AMD Ryzen 7 3700X in multi-core. You might want to take a look at that last image though, to see how well it beats the previous generation's Core i9-9900KF. Note that the 'F' indicates that there's no integrated graphics, so other than that, KF and K chips are identical.

PCMark 10

PCMark 10 has an all-in-one test that can be broken down into various segments.

Before we even look at the scores, take a look at the CPU temperature on the graph. On the first build, you'll see spikes of over 90 degrees, where it doesn't even hit 70 degrees using the Noctua cooler. In fact, the ASUS Maximus XII Extreme motherboard has a temperature gauge on it and it doesn't even go above 89 degrees, and during that first run of the test, I observed it at 89 quite a bit. With the Noctua cooler, it's not even worth checking.

When I reviewed the Core i5, the temperature was a lot closer to something that I'd call consistent. It did spike in those same two spots in the beginning, but it barely touched 90 degrees. Remember, cooling is super important. The more the CPU heats up, the worse off you're going to be in terms of performance.

The i5 build had the same parts as my first i9 build, and the i5 build scored 6,356 on this test, so there's a big difference. I'd also draw your attention to the OMEN Obelisk that I reviewed in September, which is where I got the GeForce RTX 2080 Ti and HyperX Fury memory from. That machine got a score of 7,137 with its Core i9-9900K, but keep in mind that that's more comparable to build two.

PCMark 8

PCMark 8 has several tests that we can take a look at.

The biggest improvement over the Core i5-10600K was on the Creative test, where the Core i5 got 6,539. Looking at last year's OMEN Obelisk, that got 4,731 on Home, 7,025 on Creative, and 3,683 on Work. The Work test is mostly stagnant across the board, and I'm considering just not running it anymore. Even a 15W U-series chip can beat 90% of results on that one.

Keep in mind that when I talk about the Core i5, it's best to compare that to Build one, and the OMEN Obelisk is better compared to Build two.

3DMark: Time Spy

3DMark is a great way of testing out gaming performance, although we'll look at VRMark for VR performance.

One nice thing about 3DMark is that it nicely differentiates between a CPU score and a GPU score. With the first build, the CPU score was just 9,351, and it was 13,174 on the second build. You can compare either of that to the Core i5-10600K, of course, which got 6,788.

The difference between the two builds is worth noting because with a Core i9, you're going to get much better performance than with a Core i5, no matter how you slice it. However, the parts you use with that Core i9 make a huge difference in what you can actually get out of the CPU.

VRMark

VRMark has three different tests: Orange Room, Cyan Room, and Blue Room, and that's in order of complexity. I've actually never seen a PC pass the Blue Room test, only seeing some hit bare minimum frame rates but not recommended frame rates.

It's not surprising the both of these machines easily passed the Orange Room and Cyan Room tests. Honestly, a potato could pass the Orange Room test. The Blue Room score, as mentioned, is almost never above the target frame rate, but it was passable on the second build.

Geekbench

Geekbench is a great test for straight-up CPU testing.

Build one

Build two

First of all, the Core i5-10600K got 1,237 on single-core and 5,843 on multi-core. But also, Geekbench has a whole website that you can use to check out different CPU scores. For example, an iMac from early 2019 with a Core i9-9900K for 1,269 on single-core and 8,374 on multi-core, so there are considerable improvements in this generation.

You're probably not upgrading from the last generation though. There's a Core i7-8700K that got 1,364 on single-core and 6,743 on multi-core, and a Core i7-7700K that got 1,358 on single-core and 5,541 on multi-core.

The single-core improvements over the last few years aren't entirely meaningful from one generation to the next. A lot of the big improvements come from multi-core. That top-of-the-line Core i7-7700K from just a few years ago had only four cores. These days, you get four cores in an ultrabook. When it comes to Comet Lake, the fundamental architecture of the chip really hasn't changed since Intel made the move to 14nm. There are more cores, and the TDP is jacked up, but the architecture is similar.

Cinebench

The last test that I ran is Cinebench.

The nice thing about Cinebench is that it's easy to see exactly where it stacks up against other CPUs.

Conclusion

The hardest part about reviewing the Intel Core i9-10900K is that I have no way of directly comparing it to its direct competitors, the 12-core AMD Ryzen 9 3900X and the 16-core AMD Ryzen 9 3950X, both of which are build on a 7nm process. Those support 3200MHz memory, and also, they support PCIe 4; however, they have a lower clock speed and a lower 105W TDP.

Other than the lack of PCIe 4 support, the biggest downside to all of Intel's Comet Lake S processors is that it requires a new motherboard. The good news there is that with the new board, you'll at least be covered for the next generation. In fact, LGA 1151 was supported from the sixth through ninth generations, so presumably, LGA 1200 will be supported for a few years to come.

The Core i9-10900K is an excellent CPU if you're going for powerful tasks like gaming and video editing, but it's also just a great processor. Everything is faster with the i9, even if that additional speed is overkill for the tasks that you do on a regular basis. You'll need some serious parts though. If you've got a Core i5 K-series PC from a few years ago and you're planning to bring over the same parts other than the CPU and the motherboard, expect to have to spend extra money.

The Core i9-10900K runs hot and it consumes a lot of power, but it's also very powerful. Intel jacked up the cores from eight to 10, and it increased the TDP from 95W to 125W. There's a lot that you can do here, and if you're looking for power, the i9 is the way to go.

Gallery: Intel Core i9-10900K review