Original Link: https://www.anandtech.com/show/17479/the-intel-core-i9-12900ks-review-the-best-of-intel-s-alder-lake-and-the-hottest



As far as top-tier CPU SKUs go, Intel's Core i9-12900KS processor sits in noticeably sharp In contrast to the launch of AMD's Ryzen 7 5800X3D processor with 96 MB of 3D V-Cache. Whereas AMD's over-the-top chip was positioned as the world's fastest gaming processor, for their fastest chip, Intel has kept their focus on trying to beat the competition across the board and across every workload.

As the final 12th Generation Core (Alder Lake) desktop offering from Intel, the Core i9-12900KS is unambiguously designed to be the powerful one. It's a "special edition" processor, meaning that it's low-volume, high-priced chip aimed at customers who need or want the fastest thing possible, damn the price or the power consumption.

It's a strategy that Intel has employed a couple of times now – most notably with the Coffee Lake-generation i9-9900KS – and which has been relatively successful for Intel. And to be sure, the market for such a top-end chip is rather small, but the overall mindshare impact of having the fastest chip on the market is huge. So, with Intel looking to put some distance between itself and AMD's successful Ryzen 5000 family of chips, Intel has put together what is meant to be the final (and fastest) word in Alder Lake CPU performance, shipping a chip with peak (turbo) clockspeeds ramped up to 5.5GHz for its all-important performance cores.

For today's review we're putting Alder Lake's fastest to the test, both against Intel's other chips and AMD's flagships. Does this clockspeed-boosted 12900K stand out from the crowd? And are the tradeoffs involved in hitting 5.5GHz worth it for what Intel is positioning as the fastest processor in the world? Let's find out.

Below is a list of our detailed Intel Alder Lake and Z690 coverage:

As a quick recap, we've covered Alder Lake's dual architectural hybrid design in our Core i9-12900K review, including the differences between the P (performance) and E (efficiency cores). The P-cores are based on Intel's high-performing Golden Cove architecture, which provides solid single-threaded performance. Meanwhile, the Gracemont-based E-cores, although lower-performing on their own, are smaller and draw much less power, allowing Intel to pack them in to benefit multi-threaded workloads without blowing the chips' power and thermal budgets.

The Intel Core i9-12900KS: The World's Fastest Processor

Not just content with having a solid selection of premium 12th generation Core series processors, including the then flagship Core i9-12900K, Intel a few months ago unleashed the Core i9-12900KS to the market. Primarily targeted at gamers and enthusiasts who need the very best of performance, the Core i9-12900KS is essentially a high bin version of the Core i9-12900K, but with a few (not so subtle) differences.

Based on the same Alder Lake die, both 12900Ks share the same core and thread count (8P+8E). Instead, the most significant difference comes in the speed: the Core i9-12900KS has a whopping 5.5 GHz boost core on its Performance (P) cores, which is 300 MHz higher than the regular K chip. Meanwhile the base frequencies are also improved by 200 MHz higher, leading to a chip that offers 3.4 GHz base and 5.5 GHz boost clockspeeds. That makes the Core i9-12900KS the fastest desktop processor hat Intel has ever created in terms of out-of-the-box core frequency. Even the Efficiency (E) cores have been clocked higher for this SKU, with a 100 MHz bump on both the base and boost frequencies, putting the E cores at 2.5 GHz base and a 4.0 GHz boost.

Intel 12th Gen Core i9 Series
Alder Lake
AnandTech Cores
P+E
E-Core
Base
E-Core
Turbo
P-Core
Base
P-Core
Turbo
L3
MB
iGPU
(UHD)
Base
W
Turbo
W
Price
$1ku
i9-12900KS 8+8 2500 4000 3400 5500 30 770 150 241 $739
i9-12900K 8+8 2400 3900 3200 5200 30 770 125 241 $589
i9-12900KF 8+8 2400 3900 3200 5200 30 - 125 241 $564
i9-12900F 8+8 1800 3800 2400 5100 30 - 65 202 $464
i9-12900 8+8 1800 3800 2400 5100 30 770 65 202 $489
i9-12900T 8+8 1000 3600 1400 4900 30 770 35 106 $489

The engineering tradeoff to the bump in core frequencies on both the Performance (P) and Efficiency (E) cores is that the Core i9-12900KS draws more power, with a base TDP of 150 W and a boost TDP of up to 241 W. This is an increase of 25 W for the base TDP versus the original Core i9-12900K processor, which from our experience, is already a hot running processor that can draw some serious power when overclocked. And there's room to go higher still – like other K-series chips, the 12900KS is multiplier unlocked, meaning users can attempt to overclock these chips even further.

Focusing on price, the Intel Core i9-12900KS is officially priced at $739 in for 1000 chip orders. Street pricing, in turn, is almost spot-on, with Amazon and Newegg charging $735 each. Officially this puts a $150 premium on the top-tier 12900KS, while comparing street prices it's closer to about a $175 premium right now. This also puts it $235 more expensive when directly compared to AMD's most expensive desktop chip, the Ryzen 9 5950X processor ($499), and just shy of $300 over the Ryzen 7 5800X3D ($439). Suffice it to say, when it comes to 'halo' products such as this, any notions or dreams of value typically go out of the window, and users that are looking for the fastest and greatest going to be expected to dig deep in to their wallets. 


The Core i9-12900KS hitting 5.5 GHz on P-core 4 and 5, rest of the P cores at 5.2 GHz

And while there's a significant price difference between the two, make no mistake: the Core i9-12900KS was created to go directly up against AMD's impressive Ryzen 7 5800X3D and its 96 MB of 3D L3 V-Cache. Pitched as the ultimate gaming processor, the Ryzen 7 5800X3D, as we have seen, is very potent in gaming, often vaulting to the top in CPU-limited workloads. Even factoring in the 5.5 GHz performance core boost frequencies, the large pool of L3 cache on the 5800X3D will shine in games that can utilize that extra cache. In the titles where additional cache doesn't influence performance, the insane clock speeds of 5.5 GHz will shine, or so that is the hope for Intel here.

 

The most significant benefit of Intel's Alder Lake special edition chip is that it isn't a one-trick pony; because this SKU is based on across-the-board clockspeed increases, it offers some serious horsepower for computational tasks. This is where we saw the AMD Ryzen 7 5800X3D lag behind the competition, as L3 cache typically doesn't influence the performance of rendering, encoding, and transcoding as pure core grunt does. It will be interesting to see how the Core i9-12900KS stacks up against the i9-12900K in our computational suite while it will be going metaphorically head to head with the Ryzen 7 5800X3D in our gaming suite.

Test Bed and Setup

Although there were some problems initially with the Intel Thread Director when using Windows 10 at the launch of Alder Lake, any core scheduling issues are entirely negated by using the latest Windows 11 operating system. The Intel Thread Director works in tandem with Alder Lake to assign the right P-cores and E-cores to different tasks based on the complexity and severity of the workload. We also test the Core i9-12900KS with DDR5 memory at JEDEC specifications (DDR5-4800 CL40). We are also using Windows 11, which we are using now for CPU and motherboard reviews as we advance into the rest of 2022 and beyond.

For our testing, we are using the following:

Alder Lake Test System (DDR5)
CPU Core i9-12900KS ($735)
8+8 Cores, 24 Threads
150W Base, 241W Turbo
Motherboard MSI Z690 Carbon WI-FI
Memory SK Hynix
2x32 GB
DDR5-4800 CL40
Cooling ASUS ROG Ryujin II 360mm AIO
Storage Crucial MX300 1TB
Power Supply Corsair HX850 
GPUs NVIDIA RTX 2080 Ti, Driver 496.49
Operating Systems Windows 11 Up to Date

All other chips for comparison were run as tests listed in our benchmark database, Bench, on Windows 10.



CPU Benchmark Performance: Power, Office, and Science

Our previous set of ‘office’ benchmarks have often been a mix of science and synthetics, so this time we wanted to keep our office section purely on real-world performance.

For the remainder of the testing in this review of the Core i7-12700K and i5-12600K, we are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Power

(0-0) Peak Power

Compared directly to the Core i9-12900K, the Core i9-12900KS does draw more power in our Peak Power test, albeit not immensely more. Because Intel has assigned the chip the same 241W PL1 limit as the original 12900K, in TDP-constrained scenarios both chips are held to a similar limit. Still, with a figure of 276.44 W, this is considerably more than other processors including all of AMD's premium 5000-series offerings, and Intel's 12th Gen Core i5 and i7 processors.

Office

(1-1) Agisoft Photoscan 1.3, Complex Test

In our Agisoft Photoscan 1.3 benchmark, the Core i9-12900KS is around 1.5% better than the regular i9-12900K, and considerably quicker than the rest on test.

Science

(2-1) 3D Particle Movement v2.1 (non-AVX)

(2-2) 3D Particle Movement v2.1 (Peak AVX)

(2-3) yCruncher 0.78.9506 ST (250m Pi)

(2-4) yCruncher 0.78.9506 MT (2.5b Pi)

(2-5) NAMD ApoA1 Simulation

In our science-based benchmarks, the Core i9-12900KS and the Core i9-12900K trade blows which is to be expected with two similar processors, albeit the extra core clock speeds on the i9-12900KS do not show as much benefit as the price difference would suggest. 



CPU Benchmark Performance: Simulation And Rendering

Simulation and Science have a lot of overlap in the benchmarking world, however for this distinction we’re separating into two segments mostly based on the utility of the resulting data. The benchmarks that fall under Science have a distinct use for the data they output – in our Simulation section, these act more like synthetics but at some level are still trying to simulate a given environment.

We are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Simulation

(3-2a) Dwarf Fortress 0.44.12 World Gen 65x65, 250 Yr

(3-2b) Dwarf Fortress 0.44.12 World Gen 129x129, 550 Yr

(3-2c) Dwarf Fortress 0.44.12 World Gen 257x257, 550 Yr

(3-3) Dolphin 5.0 Render Test

(3-4a) Factorio v1.1.26 Test, 10K Trains

(3-4b) Factorio v1.1.26 Test, 10K Belts

(3-4c) Factorio v1.1.26 Test, 20K Hybrid

When it comes to simulation, the higher core clock speeds of the Core i9-12900KS didn't make any effect in our Factorio benchmark, which AMD's Ryzen 7 5800X3D with 3D V-Cache gives a more effective boost to performance. In our Dolphin test, the Core i9-12900KS was quicker by around 7-8%, and in our Dwarf Fortress benchmark, the Core i9-12900KS was better than the K, but not as good as the Ryzen 7 5800X3D.

Rendering

(4-1) Blender 2.83 Custom Render Test

(4-2) Corona 1.3 Benchmark

(4-4) POV-Ray 3.7.1

(4-5) V-Ray Renderer

(4-6a) CineBench R20 Single Thread

(4-6b) CineBench R20 Multi-Thread

(4-7a) CineBench R23 Single Thread

(4-7b) CineBench R23 Multi-Thread

Focusing on rendering performance, the results between the Core i9-12900KS and Core i9-12900K are consistently close. In single-threaded benchmarks such as CineBench R23, we saw impressive performance in comparison to other chips on test, with a 7% jump in R23 single thread performance over the Core i9-12900K.

The multi-threaded performance though between the two Intel 12th Gen Core i9 chips wasn't much difference, but there's a clear advantage in single-thread performance when rendering. It's worth pointing out that rendering is typically a multi-threaded workload.



CPU Benchmark Performance: Encoding and Compression

One of the interesting elements on modern processors is encoding performance. This covers two main areas: encryption/decryption for secure data transfer, and video transcoding from one video format to another.

In the encrypt/decrypt scenario, how data is transferred and by what mechanism is pertinent to on-the-fly encryption of sensitive data - a process by which more modern devices are leaning to for software security.

Video transcoding as a tool to adjust the quality, file size and resolution of a video file has boomed in recent years, such as providing the optimum video for devices before consumption, or for game streamers who are wanting to upload the output from their video camera in real-time. As we move into live 3D video, this task will only get more strenuous, and it turns out that the performance of certain algorithms is a function of the input/output of the content.

We are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Encoding

(5-1a) Handbrake 1.3.2, 1080p30 H264 to 480p Discord

(5-1c) Handbrake 1.3.2, 1080p30 H264 to 4K60 HEVC

(5-2a) 7-Zip 1900 Compression

(5-2b) 7-Zip 1900 Decompression

(5-2c) 7-Zip 1900 Combined Score

(5-3) AES Encoding

(5-4) WinRAR 5.90 Test, 3477 files, 1.96 GB

In the Encoding and Compression section of our CPU benchmark suite, the Core i9-12900KS was either around the same or performed slightly better than the Core i9-12900K. The Core i9-12900KS was also consistently better than the AMD Ryzen 7 5800X3D in all encoding tests except in our WinRAR 5.90 benchmark.



CPU Benchmark Performance: Legacy and Web

In order to gather data to compare with older benchmarks, we are still keeping a number of tests under our ‘legacy’ section. This includes all the former major versions of CineBench (R15, R11.5, R10) as well as x264 HD 3.0 and the first very naïve version of 3DPM v2.1. We won’t be transferring the data over from the old testing into Bench, otherwise, it would be populated with 200 CPUs with only one data point, so it will fill up as we test more CPUs like the others.

The other section here is our web tests.

We are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Legacy

(6-1a) CineBench R10 ST

(6-1b) CineBench R10 MT

(6-2a) CineBench R11.5 ST

(6-2b) CineBench R11.5 MT

(6-3a) CineBench R15 ST

(6-3b) CineBench R15 MT

(6-4a) 3DPM v1 ST

(6-4b) 3DPM v1 MT

(6-5a) x264 HD 3.0 Pass 1

(6-5b) x264 HD 3.0 Pass 2

Focusing on our older Legacy benchmarks, the Core i9-12900KS is consistently the best performer of all of the processors on test. The additional frequency bumps to both the Performance (P) and Efficiency (E) cores make it slightly better than the Core i9-12900K.

Web

(7-1) Kraken 1.1 Web Test

(7-2) Google Octane 2.0 Web Test

(7-3) Speedometer 2.0 Web Test

Looking at the performance in our web-based tests, the Core i9-12900KS again beats the competition pretty comprehensively, including the Core i9-12900K, the AMD Ryzen 9 5950X, and the Ryzen 7 5800X3D.



Gaming Performance: iGPU

All of our game testing results, including other resolutions, can be found in our benchmark database: www.anandtech.com/bench. All gaming tests here were run using integrated graphics, with a variation of 720p resolutions and at minimum settings.

We are using DDR5 memory for Alder Lake at the following settings:

  • DDR5-4800(B) CL40

All of AMD's Ryzen APUs were tested with DDR4 memory at the relevant JEDEC specifications of each chip.

Final Fantasy 14

IGP Final Fantasy 14 - 768p Min - Average FPS

World of Tanks

IGP World of Tanks - 768p Min - Average FPS

Borderlands 3

IGP Borderlands 3 - 360p VLow - Average FPS

Far Cry 5

IGP Far Cry 5 - 720p Low - Average FPS

Gears Tactics

IGP Gears Tactics - 720p Low - Average FPS

Grand Theft Auto V

IGP Grand Theft Auto V - 720p Low - Average FPS

Strange Brigade (DirectX 12)

IGP Strange Brigade DX12 - 720p Low - Average FPS

Looking at the performance between Intel's UHD 770 integrated graphics and AMD's Ryzen APUs, it's clear that the APUs perform much better in all of the games that require more intensive graphics. It's worth mentioning that Intel hasn't put as much investment into its die space for the iGPU to be as effective, and Intel is just hitting the bare minimum here for games at lower resolutions.



Gaming Performance: 1080p

All of our game testing results, including other resolutions, can be found in our benchmark database: www.anandtech.com/bench. All gaming tests were with an RTX 2080 Ti.

We are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Civilization VI

(b-7) Civilization VI - 1080p Max - Average FPS

(b-8) Civilization VI - 1080p Max - 95th Percentile

Final Fantasy 14

(d-4) Final Fantasy 14 - 1080p Max - Average FPS

Final Fantasy 15

(e-3) Final Fantasy 15 - 1080p Standard - Average FPS

(e-4) Final Fantasy 15 - 1080p Standard - 95th Percentile

World of Tanks

(f-3) World of Tanks - 1080p Standard - Average FPS

(f-4) World of Tanks - 1080p Standard - 95th Percentile

(f-5) World of Tanks - 1080p Max - Average FPS

(f-6) World of Tanks - 1080p Max - 95th Percentile

Borderlands 3

(g-7) Borderlands 3 - 1080p Max - Average FPS

(g-8) Borderlands 3 - 1080p Max - 95th Percentile

Far Cry 5

(i-7) Far Cry 5 - 1080p Ultra - Average FPS

(i-8) Far Cry 5 - 1080p Ultra - 95th Percentile

Gears Tactics

(j-7) Gears Tactics - 1080p Ultra - Average FPS

(j-8) Gears Tactics - 1080p Ultra - 95th Percentile

Grand Theft Auto V

(k-7) Grand Theft Auto V - 1080p Max - Average FPS

(k-8) Grand Theft Auto V - 1080p Max - 95th Percentile

Red Dead Redemption 2

(l-7) Red Dead 2 - 1080p Max - Average FPS

(l-8) Red Dead 2 - 1080p Max - 95th Percentile

Strange Brigade (DirectX 12)

(m-7) Strange Brigade DX12 - 1080p Ultra - Average FPS

(m-8) Strange Brigade DX12 - 1080p Ultra - 95th Percentile

Strange Brigade (Vulcan)

(n-7) Strange Brigade Vulkan - 1080p Ultra - Average FPS

(n-8) Strange Brigade Vulkan - 1080p Ultra - 95th Percentile

Looking at gaming with our NVIDIA GeForce RTX 2080 Ti at 1080p resolutions, the Core i9-12900KS performed respectably in all of the titles tested. It either traded blows directly with the Core i9-12900K or beat it where the extra clock speed made a difference, especially in Final Fantasy 14 and World of Tanks.



Gaming Performance: 4K

All of our game testing results, including other resolutions, can be found in our benchmark database: www.anandtech.com/bench. All gaming tests were with an RTX 2080 Ti.

We are using DDR5 memory at the following settings:

  • DDR5-4800(B) CL40

Civilization VI

(b-5) Civilization VI - 4K Min - Average FPS

(b-6) Civilization VI - 4K Min - 95th Percentile

Final Fantasy 14

(d-3) Final Fantasy 14 - 4K Min - Average FPS

Final Fantasy 15

(e-5) Final Fantasy 15 - 4K Standard - Average FPS

(e-6) Final Fantasy 15 - 4K Standard - 95th Percentile

World of Tanks

(f-7) World of Tanks - 4K Max - Average FPS

(f-8) World of Tanks - 4K Max - 95th Percentile

Borderlands 3

(g-5) Borderlands 3 - 4K VLow - Average FPS

(g-6) Borderlands 3 - 4K VLow - 95th Percentile

Far Cry 5

(i-5) Far Cry 5 - 4K Low - Average FPS

(i-6) Far Cry 5 - 4K Low - 95th Percentile

Gears Tactics

(j-5) Gears Tactics - 4K Low - Average FPS

(j-6) Gears Tactics - 4K Low - 95th Percentile

Grand Theft Auto V

(k-5) Grand Theft Auto V - 4K Low - Average FPS

(k-6) Grand Theft Auto V - 4K Low - 95th Percentile

Strange Brigade (DirectX 12)

(m-5) Strange Brigade DX12 - 4K Low - Average FPS

(m-6) Strange Brigade DX12 - 4K Low - 95th Percentile

Strange Brigade (Vulkan)

(n-5) Strange Brigade Vulkan - 4K Low - Average FPS

(n-6) Strange Brigade Vulkan - 4K Low - 95th Percentile

When gaming at 4K resolutions, the Core i9-12900KS performs very well, although the Core i9-12900K does outperform it in a couple of games. It's also worth noting that in our game benchmark suite, the Core i9-12900KS for the better part, actually outperforms the AMD Ryzen 7 5800X3D, but the latter almost certain wins in situations where more L3 cache is favored by the game title.



Conclusion

When Intel brought its 12th Generation Core series to the market, it not only took the fight to AMD and Ryzen 5000 in terms of performance, but it also marked a significant shift in its approach to pricing. And, for a while at least, there has been balance in the market between AMD and Intel. But of course, balance is not what either company wants – they're in it to win it – helping to give rise to more unusual one-off parts like the Core i9-12900KS and the Ryzen 7 5800X3D.

This late-generation part, to that end, is a clear effort by to get one step ahead of AMD by countering AMD's efforts with the L3 cache-heavy Ryzen 7 5800X3D, as well as to protect Intel's overall leadership position with respect to having the fastest desktop processor.  Ultimately, Intel opted to make their stand with their new – but equally not new – special edition i9-12900KS processor. Armed with a boost core clock speed of up to 5.5 GHz on two of the performance cores, with a general bump of 100 MHz on the efficiency cores, on paper, the Core i9-12900KS looks like an even faster version of the already powerful and plenty capable i9-12900K.

But because it's fundamentally a higher clocked i9-12900K, aside from a few changes such as the 150 W base TDP and faster core clock speeds on both the P and E cores, the Core i9-12900KS and the Core i9-12900K are otherwise the same chips, with the KS merely being a better bin. Still, Intel is in a very good position to justify this new highly overclocked and special binned processor as an enthusiast-grade processor for desktops, which makes it the 'fastest desktop processor' that Intel has ever launched to market.

In both theory and practice, then, Intel's claims are correct: the Core i9-12900KS is the fastest processor on the market. To be sure, it doesn't win every benchmark, but on balance it's enough to give Intel an edge, especially away from games where AMD's 5800X3D fares so well due to its large L3 cache.

With all of that said, the i9-12900KS isn't just a typical run-of-the-mill processor that anyone could just plop into their system without some critical planning. It's a fast chip, but it's also a hot chip and an expensive chip that that beats its predecessor by a performance margin much smaller than the price margin. So whether it's "worth it" is very much situational – mostly with regards to the depths of a buyer's wallet.

Let's take a look at the performance elements and then dive into the nuances:

Core i9-12900KS Compute Performance Analysis: A Singular Victor

As the Core i9-12900KS was created as a rally against AMD's Ryzen 7 5800X3D with 96 MB of L3 3D V-Cache, the performance in computational workloads is dominated by Intel's 12th Gen Core. This is a mixture of an intelligent yet highly functional design with its hybrid core architecture and improved IPC performance and core clock speeds compared to the previous 11th Core Series processors.

(4-7a) CineBench R23 Single Thread

Even when compared directly to the Core i9-12900K, the Core i9-12900KS has the same foundational architecture, but it's basically on steroids, with two cores boosting up to 5.5 GHz for incredible single-threaded performance. In the CineBench R23 single-threaded test, the Core i9-12900KS was 7.2% better than the Core i9-12900K and a whole 29% faster than AMD's premium Ryzen 9 5950X processor.

(4-7b) CineBench R23 Multi-Thread

Regarding multi-threaded workloads, the Core i9-12900KS once again proved fruitful, but only very marginally (0.2%) better than the Core i9-12900K. Part of this is down to power limitations and heat dissipation, as the Core i9-12900KS at default settings is nothing short of scorching hot. And in other multi-threaded workloads it's much the same story, with the the Core i9-12900KS and i9-12900K consistently trading blows in terms of performance.

(3-3) Dolphin 5.0 Render Test

In our Dolphin 5.0 rendering benchmark, the Core i9-12900KS showed its superiority over the competition with a speedy result of 169 seconds. It was 8% quicker than the Core i9-12900K and around 25% quicker than the beefy AMD Ryzen 9 5950X. 

Throughout our computational benchmarks, the Core i9-12900KS had some good wins, especially against the rival it was created to beat, the AMD Ryzen 7 5800X3D. Not only does it outperform this comfortably, but as Intel claims it is, it is the fastest desktop processor currently on the market. It wholeheartedly does enough to stake its claim.

Core i9-12900KS Gaming Performance Analysis: Mixed Company

When it comes to gaming performance, the Core i9-12900KS is highly competitive, but where it finally ends up really depends on the title. If large amounts of L3 cache can influence the game, then the Ryzen 7 5800X3D with 96 MB will shine like the star it is.

(b-5) Civilization VI - 4K Min - Average FPS

In our Civilization VI benchmark at 4K resolutions, AMD's Ryzen 7 5800X3D reigns supreme, with the Core i9-12900KS running with around 6% fewer frames on average. It's also only about 3% quicker than the Core i9-12900K. Just like in our computational testing, in some areas, the i9-12900K can actually be marginally better depending on the intensity of the game on the CPU.

Whereas when clock speeds and IPC play a more vital role, Intel's Alder Lake architecture sits ahead of the competition.

(f-5) World of Tanks - 1080p Standard - Average FPS

Looking at performance in World of Tanks at 1080 Max settings, the Core i9-12900KS pulls ahead of the competition when using our NVIDIA GeForce RTX 2080 Ti.

In summary, gaming performance comes down to a couple of things. If the game title can benefit from L3 cache, the Ryzen 7 5800X3D is (still) the chip to go for. But if the game doesn't, both the Core i9-12900KS and Core i9-12900K trade blows consistently, while the raw IPC advantage and clock speeds tend to keep the two of them ahead of anything else.

Core i9-12900KS: Fastest Desktop CPU, But Not Without Issues

When you consider the regular Core i9-12900K processor, this is typically hot and power draining at default settings. Even in our Z690 motherboard testing, we regularly hit over 400 W when loading up the processor when overclocking to 5.3 GHz all-core. Meanwhile the Core i9-12900KS pushes even harder, with two cores at 5.5 GHz at stock with Thermal Velocity Boost and Adaptive Boost enabled.

Using the integrated logging feature on the HWInfo monitoring software, we ran CineBench R23's multi-threaded test on a 5-minute loop to show where the Core i9-12900KS isn't quite so strong. Focusing first on the CPU V-Core of the Core i9-12900KS on our MSI Z690 Carbon WIFI, we saw an average V-Core of 1.409 V at the beginning of the test.

This quickly dropped down to around 1.17 to 1.20 V once the main bulk of the load was applied as the temperatures rapidly spiraled out of control to 100°c very quickly. Once the test refreshed, the CPU V-Core would rise back up to around 1.368 V, and once the load was applied, it would promptly drop again due to the thermal throttling.

Using the same data, above, we have the average CPU Package temperature across the 5-minute loop of CineBench R23. As with the CPU V-Core, once the intense multi-threaded workload was applied to the processor, it would quickly slam into the 100°C mark, which would throttle the processor back to try and alleviate the temperatures.

Not to be outdone by a potentially faulty cooler, I swapped out our ASUS ROG Ryujin II 360 mm AIO cooler for another 360 mm AIO from MSI. We saw worse performance here and confirmed that it wasn't our cooling that was the problem, but the Core i9-12900KS – or at least our i9-12900KS – is ridiculously hot under load.


Screenshot of monitoring panel on Intel's XTU after a benchmark run; thermal throttling is an issue

One potential workaround to this would be to use more aggressive cooling methods such as a custom water loop. Still, even with our highly premium $310 cooler, we consistently hit 100°C on the heavier workloads, which would explain why performance was around 5% to 7% better than the regular Core i9-12900K. Even with thermal throttling on some of the tests, the Core i9-12900KS was still as powerful, but it seems that cooling is the apparent limiting factor to squeezing out extra performance.

It's worth noting that custom water cooling is far from cheap, and even the Core i9-12900KS has a hefty price premium of $739 to contend with. Users looking to install one of these hoping that performance will just come without any penalty with any type of cooling are sadly mistaken. The fact here is that the cooler the Core i9-12900KS runs, and thus the less thermal throttling it encounters, should translate into better performance.

Final Words: Core i9-12900KS Runs Fast but Too Darn Hot – Aggressive Cooling Required

Summarizing this review, the Core i9-12900KS is a very fast chip when it comes strict to performance. But overall we find it something of a mixed bag, and perhaps foolishy, we expected a little more.

The Core i9-12900KS has a 1K per unit price of $739 but can be found for $735 at both Amazon and Newegg at the time of writing. This is certainly not your everyday run-of-mill processor for your average system, it's an enthusiast-grade processor, which is, and I quote, the fastest desktop processor on the market right now. 

Given that we're talking about what's essentially just a higher clocked Core i9-12900K, the biggest question is, is it worth the additional $145 over the regular i9-12900K ($590)? The short answer is "not really," especially when you factor in the additional cooling challenges that come with such an extreme chip. But then, if you're even considering buying an Intel KS processor, you already know that it's a part focused on absolute performance, and not being a value (or easy cooling) proposition.

As with many halo products over the years, the Core i9-12900KS is the best of the best that Intel has to offer in the desktop space right now, not just from a single and multi-threaded point of view, but it really just is an impressive feat of engineering to be able to hit 5.5 GHz out of the box on any core, let alone two of them.


The Intel Core i9-12900KS CPU box insert; gold wafer theme.

This brings the pitfalls into play, including heat and power consumption. The Core i9-12900KS requires incredible cooling to keep things under control, with around 240 W of power pretty much consistently when under load and sometimes more when there's enough thermal headroom to play with. The heaviest workloads will surpass the 241 W PL1 and PL2 power limits when they are disabled, and the performance difference is marginal even with them enabled. Intel's Thermal Velocity Boost is very effective at balancing the hot cores and throttling them independently, so all of that performance is not lost, but rather merely capped.

Overall the Core i9-12900KS is an impressive processor for top-tier desktop performance, both in compute and gaming. The drawback is that there is some performance loss from thermal throttling, but for users with elaborate custom water cooling, this shouldn't be as much of a problem. For the price, however, there's little to no value to be had from this processor at $735, especially when the Core i9-12900K is considerably cheaper at $590.

 

Even with the thermal throttling, the performance is still impressive and as we've mentioned, expect to require $400+ of custom water cooling to even make a dent into the heat that the Core i9-12900KS generates. The idea and concept is fantastic, but the execution with high CPU V-Cores required to sustain the clock speeds and consequently higher thermal requirements make things a tough pill to swallow for all but the most hardcore computing enthusiast.

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