Intel Core i5-12600K and Core i9-12900K review: Alder Lake is a total game-changer

Intel Core i5-12600K and Core i9-12900K review: Alder Lake is a total game-changer

Last week, Intel announced its 12th-generation processors, codenamed Alder Lake. After six generations (yes, six) of using 14nm nodes, the company made a radical change in the architecture. In fact, this could be the biggest change since Intel adopted AMD’s 64-bit architecture that was based on x86.

On top of being built on the new Intel 7 node, it also uses the company’s hybrid technology. For a bit of background, it’s something that ARM chips have been doing for ages. It uses powerful cores to handle the big tasks, and more efficient cores to handle smaller tasks. That way, when background tasks are being performed, the machine uses less power. Intel first did this in its Lakefield chips, which were meant for ultra-mobile devices like foldable and dual-screen PCs.


While we knew that Alder Lake would be hybrid, it came as a bit of a surprise that Intel started off with desktop chips. Surely, you’d expect that something that’s all about conserving power would start out in battery-based devices. As it turns out, this also results in a boost in performance, especially when multitasking. It allows for more cores and more threads, with Intel Thread Director managing what to run on which core.

It’s really good. The processors are much more powerful. In fact, even the E-cores (efficient cores) are a tiny bit more powerful than 10th-generation cores. On top of all of that, it comes with support for DDR5 memory and PCIe 5.0, so it’s all pretty fantastic.

Intel Core i5-12600K and Core i9-12900K Specs

Core i5-12600K Core i9-12900K
Lithography Intel 7 Intel 7
Total cores (P + E) 10 (6 + 4) 16 (8 + 8)
Threads 16 24
P-core Frequency 3.7GHz (Max 4.9GHz) 3.2GHz (5.1GHz Max, 5.2GHz Intel Turbo Boost Max Technology 3.0)
E-core Frequency 2.8GHz (Max 3.6GHz) 2.4GHz (3.9GHz Max)
Cache 20 MB Intel Smart Cache 30 MB Intel Smart Cache
L2 Cache 9.5 MB 14 MB
Base power 125W 125W
Turbo power 150W 241W
Max Memory Size 128GB 128GB
Memory Types Up to DDR5 4800 MT/s
Up to DDR4 3200 MT/s
Up to DDR5 4800 MT/s
Up to DDR4 3200 MT/s
Number of memory channels 2 2
Max Memory Bandwidth 76.8 GB/s 76.8 GB/s
Graphics Intel UHD Graphics 770 Intel UHD Graphics 770
Graphics frequency 300MHz (1.45GHz Max) 300MHz (1.55GHz Max)
Execution units 32 32
Max resolution HDMI: 4096 x 2160 @ 60Hz
DP: 7680 x 4320 @ 60Hz
eDP – integrated flat panel: 5120 x 3200 @ 120Hz
HDMI: 4096 x 2160 @ 60Hz
DP: 7680 x 4320 @ 60Hz
eDP – integrated flat panel: 5120 x 3200 @ 120Hz
Number of displays supported 4 4
PCIe Revision 5.0 and 4.0 5.0 and 4.0
PCIe configurations Up to 1×16+4, 2×8+4 Up to 1×16+4, 2×8+4
Max number of PCIe lanes 20 20
Socket FCLGA1700 FCLGA1700
Thermal solution specification PCG 2020A PCG 2020A
Package size 45.0 mm x 37.5 mm 45.0 mm x 37.5 mm
Price $289.00 – $299.00 $589.00 – $599.00

The rig

Of course, the CPU is just one part of the PC. The graphics card is the next thing that comes to mind, obviously, but storage, and memory are just as important to the experience. So is the CPU cooler, as the cooler a CPU is, the better it performs. It even comes down to thermal compound. Indeed, a PC is a giant unit with a bunch of parts working together, any one of which can bottleneck the whole thing.

Intel Core parts and motherboard on black desk

We’re here to review the new CPUs, but of course, Alder Lake unlocks new components like faster DDR5 memory. Intel supplied the CPUs – both the Core i5-12600K and Core i9-12900K – the ASUS ROG Strix Z690-E Gaming Wi-Fi motherboard, and Corsair DDR5 memory. Corsair had also promised to deliver a CPU cooler, but it never actually did. I ended up grabbing an LGA 1700 bracket off of Amazon for my Noctua NH-U12A.

I know that some of these aren’t the sexiest parts in the world. The bottleneck on this system is the SATA SSD. Hopefully by the next time I do one of these reviews, that’s upgraded.

Fun fact: I actually bought all of this stuff last year when Intel sent over its 10th-gen CPUs. I had never reviewed a CPU before, and all it sent was a Core i5-10600K, Core i9-10900K, and an ASUS ROG Maximus Extreme XII motherboard. It was up to me to acquire the rest…while all of the stores were closed and working on a deadline. That ended up being one of the most fun projects I’ve done. Who doesn’t love racing around to find PC parts?

Anyway, this PC is the same, but with a new motherboard, CPU, and memory.

Intel 12th-gen ‘Alder Lake’ requires a new LGA 1700 socket

It’s worth noting that the new 12th-gen processors require a new LGA 1700 socket, so you absolutely need a new motherboard. 10th-gen chips had introduced the LGA 1200 socket, and before that, Intel had used LGA 115x since sixth-gen.

Intel 12th-gen and 10th-gen processor

As you can see, the chips, and therefore the sockets, are much bigger. The good news is that while you definitely need a new motherboard, you might not need a new CPU cooler. For most of them, you can just get a new mounting bracket. Some companies, like Noctua, are offering the new brackets for free if you provide proof of purchasing. I spent around $9 on Amazon to get mine, just because it would arrive quicker.

Check out our guide on LGA 1700 coolers for more information around this.

Intel 12th-gen ‘Alder Lake’ performance

I think it’s fair to say that the Core i9-12900K is the best that there is right now. Obviously, it’s the latest and greatest from Intel, and it comes with significant architectural improvements. When I reviewed Intel’s 10th-gen CPUs (I never reviewed 11th-gen, except for some pre-built desktops that came across my desk), they were lacking some key features that AMD was offering, such as support for PCIe 4.0. Now, Intel is beating AMD to the punch with PCIe 5.0.

The Core i5-12600K, while still being pretty great, is meant to be more mainstream. Intel’s 12th-gen lineup pretty much consists of three chips (six total, since each one has a variant without integrated graphics). There’s the Core i5-12600K, the Core i7-12700K, and the Core i9-12900K. The Core i9-12900K is enthusiast level, and you’re paying enthusiast prices for it. On the other hand, the Core i5-12600K costs half the price of the Core i9.

Intel 12th-gen Core processor in LGA 1700 socket

The Core i9-12900K is the best there is right now.

These are gaming CPUs, or at least CPUs that are meant to deliver performance. The ‘K’ suffix means that these processors can be overclocked, and if you see an ‘F’, that means that there are no integrated graphics. You’re going to see a lot more 12th-gen SKUs moving forward, including mainstream ones that don’t have a ‘K’ at the end.

While those chips have historically been 65W (Intel says it’s not saying TDP anymore, since it’s not accurate with the way that its modern chips work), K-series processors have offered a higher wattage. With this generation, it starts at 125W, with the Core i9 being able to be boosted up to 241W. That’s a lot of power from one CPU.

As you’d expect, I ran a whole bunch of benchmarks on both of these. After all, that’s why you’re here, right? You’re here to see how these things stack up.

Intel Content Creation Test

The first test was one that Intel provided. It’s an automated series of processes that works through tasks in Adobe Lightroom Classic and Premiere Pro.

Core i5-12600K

Core i9-12900K

This test is designed to show off the CPU’s multitasking chops. Remember, that’s what these processors are all about. The Core i9-12900K offers a whopping 24 threads, while the Core i5-12600K is no slouch with 16. If we look at the median result, the Core i9 comfortable beat the Core i5 in all tests.

In fact, there’s so little variation between all seven of the runs that the difference between the two CPUs is quite clear. This should give you a bit of an idea between which one you want to buy, and if you want something in-between, you can check out the Core i7-12700K.


CPU-Z is a nice way to run CPU benchmarks, as well as view information about the PC. You’ll see that there are a lot of tests that focus on the CPU, and some that focus on the system as a whole.

Core i5-12600K

Core i9-12900K

The Core i9-12900K is cheaper than an AMD Ryzen 9 5950X, and offers better single-core performance.

CPU-Z also makes it each to compare the score to other CPUs. There’s a dropdown list that offers a wide array of comparable chips. I chose the Core i9-10900K to compare it to, so you can easily see how the Core i9-12900K beats the heck out of it. Even the Core i5-12600K holds its own, winning in single-core performance and coming close in multi-core. For comparison, AMD’s Ryzen 9 5950X, which has 16 cores and 32 threads, gets 648 on single-core and 11,906 on multi-core. That chip also retails for $799, so for over $200 less, Intel is delivering much better single-threaded performance and comparable multi-threaded performance, all while using less power on fewer cores.

Geekbench 5

Geekbench 5 is another test that takes a look at the CPU. It’s also easy to go on the Geekbench website and see how these scores compare to other processors.

Core i5-12600K

Core i9-12900K

Probably the thing I find most interesting is that the single-core speeds aren’t that much better on the Core i9-12900K, although that would likely change if we pushed it to its max performance. The multi-core scores on the Core i9 really blow away the Core i5 though. It’s not surprising, but I will say that it’s quite remarkable.

Cinebench R23

OK, you’re probably getting tired of straight CPU benchmarks, so this is the last one.

Once again, the single-core score is only marginally better on the Core i9, but the MP ratio is so much higher.


3DMark offers a wide variety of tests, but I chose three: Time Spy, Time Spy Extreme, and CPU Profile.

Core i5-12600K

Both Time Spy tests offer a total score that’s based on both the CPU and the GPU, but it breaks down the score of each. For the Core i5-12600K, the total Time Spy score with the RTX 2080 Ti GPU beat 94% of other PCs tested. For Time Spy Extreme, it beat 81% of results.

Core i9-12900K

In Time Spy, the Core i9 beat 96% of other results, while in Time Spy Extreme, it beat the same 81% of results. As you can see, there isn’t that big of a difference here, meaning that this test probably relies on single-threaded performance, for the most part. Indeed, multitasking is really where you’re going to see the benefit of the Core i9.


VRMark offers three tests: Orange Room, Cyan Room, and Blue Room. The Orange Room test is the easiest one, and for Blue Room, I’ve only seen one or two PCs pass it with flying colors.

Core i5-12600K

Core i9-12900K

Both of these rigs beat 99% of other results in the Orange Room test. They both got the same 86% on the Cyan Room test, and they both beat 79% of other PCs in the Blue Room test.

PCMark 10

PCMark 10 offers an all-in-one test, which covers pretty much everything.

Core i5-12600K

Core i9-12900K

Once again, the score on the Core i9 is a solid bit better than the Core i5. It’s interesting to see the different margins on different tests, because many tests simply don’t take advantage of the new architecture. Still, the Core i5-12600K beat 97% of other results, while the Core i9-12900K beat 99% of other results.

Gears 5

I did say that these are gaming CPUs, so I figured I should run at least one gaming benchmark. I went with Gears 5, frankly because of its availability with Xbox Game Pass Ultimate.

Core i5-12600K

Core i9-12900K

At this point, it’s pretty much a GPU test. I didn’t run the test using the integrated graphics because seriously, if you buy one of these processors and you’re not getting a dedicated GPU, you’re doing it wrong.

Conclusion: Should you buy an Intel 12th-gen ‘Alder Lake’ CPU?

Let’s start with the bad news, since I really didn’t say anything negative about Intel’s 12th-gen ‘Alder Lake’ processors. You’ll pretty much have to build a whole new PC for this. Not only are you going to have to shell out hundreds of dollars on a new CPU, but you’ll need a new motherboard. You’re also probably going to want to invest in some DDR5 memory. At this point, you’re looking at spending around a thousand dollars, at best.

The Core i5-12600K brings strong performance to the mainstream price point.

That’s the bad news, and I don’t even blame Intel. These products are fundamentally different from the ones that we’ve seen for years, so you shouldn’t be surprised that the chips require a new socket, and therefore a new board. It just makes this a very expensive upgrade, one that’s way more expensive than the price of the CPU. What we can blame Intel for is introducing the LGA 1200 socket with 10th-gen. Remember, 11th-gen processors only shipped earlier this year; they’re still pretty new. 10th-gen only came out in the middle of 2020. That’s a really brief time to introduce a new socket and then retire it.

Insider of computer with LED lighting

The good news is that companies like Noctua are offering free upgrade kits, and of course, you can reuse other parts of your old PC.

I have to say though, these CPUs are phenomenal. For most people, the Core i5-12600K is a dream. I say it’s great for most people because many of us won’t benefit from the big boost in multitasking performance that the Core i9 provides. The Core i5-12600K is powerful, it gets the job done, and it’s even overclockable.

The Core i9-12900K is just next-level. It’s what you get when you want the best, and indeed, I’d take it over anything that AMD has to offer.

I’ll tell you what really has me excited. Intel still hasn’t told the mobile side of the Alder Lake story, and I assume that’s coming at CES. It’s pretty wild to announce new hybrid chips that take advantage of a new power-saving technology, and lead off with the desktop processors. It’s going to be really cool to see what Intel does with mobile, and how it plans to counter Apple’s M1 series of processors. If you’re looking for a new laptop instead of building a new desktop, you might want to keep an eye out for CES.

    The Intel Core i9-12900K is the best that it has to offer, and the new generation has hybrid technology, DDR5 support, PCIe 5 support, and more.




    The Intel Core i5-12600K is the mainstream option, offering hybrid technology at a mainstream price point




About author

Rich Woods
Rich Woods

Managing Editor for XDA Computing. I've been covering tech from smartphones to PCs since 2013. If you see me at a trade show, come say hi and let me ask you weird questions about why you use the tech you use.

We are reader supported. External links may earn us a commission.