Intel Core i9-11900K CPU Review

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Conclusion

We are finally able to bring you our full in-depth review on the Intel Core i9-11900K Rocket Lake 11th Gen Core Desktop CPU.  In this review, we have shown you performance with and without the Intel Adaptive Boost Technology.  We think this is unique because as you can see in our testing the option can and does make a difference. 

We also compared the CPU against the Ryzen 9 5900X, with which it shares a common price tag.  We also included the Ryzen 7 5800X with which it shares the same core and thread count.  We also included the Intel Core i9-10900K previous generation to see the progression. 

We performed a lot of synthetic benchmarks testing both multi-threading and single-thread performance, and several games at both 1080p and 4K performance.  We now have a clearer picture of how the Rocket Lake architecture has shaped up and what kind of mold it fits into.  Specifically, we also know what value the Intel Core i9-11900K holds, and where that fits in.

Intel Adaptive Boost Technology

Let’s first discuss the Intel Adaptive Boost Technology.  This technology may be controversial amongst enthusiasts.  Intel employs a lot of boost technologies in its CPUs today.  It’s honestly hard to keep track of all of them and exactly what they do and how they interact with each CPU. 

On the Intel Core i9 lineup alone you have: Intel Turbo Boost Technology 2.0, Intel Turbo Boost Max Technology 3.0, Intel Thermal Velocity Boost, Intel All Core Turbo Frequency, and then how all these technologies interact with the single-core or all-core boost.  Now we have yet another one to keep track of, Intel Adaptive Boost Technology. 

What makes this controversial though is whether you consider that overclocking.  According to Intel’s official word on the subject, Intel does not consider it overclocking.  It backs up this statement by stating that the CPU still runs within the spec’s “current and temperature limits.”  However, it does require you have good power delivery and a good cooling solution.  The cooling solution will be the primary factor as to this feature actually working, and how well it works, and for how long it maintains the clock frequency under load. 

The other factor is that by default, right now, the Intel Adaptive Boost Technology is disabled by default in the BIOS.  You must manually go into your BIOS and manually enable this feature to benefit from it.  If you do not, the default operation will be disabled.  This is why we wanted to include both On and Off results in our graphs, so you can see what the default performance is, and then how much it could potentially help.

The other drawback is the huge power demand and thermal increase.  We experienced a large power demand enabling it, and a big temperature increase.  In reality, though, the feature was the catalyst for boosting the Core i9-11900K above the Ryzen 7 5800X if it was lagging behind.  It needed it to be competitive with the Ryzen 7 5800X.  But that is the extent of it, it was never enough to really give the Ryzen 9 5900X a run for its money.  In this case, the Ryzen 9 5900X’s core difference made a larger impact.

Where Does it Fit?

The big question for everyone is where does the Intel Core i9-11900K, or Rocket Lake for that matter, fit.  According to our testing the new Rocket Lake 11th Gen Core Desktop CPUs have improved versus their 10th Gen Comet Lake CPUs.  We saw indications that at an architectural level, there are many improvements to performance in specific workloads. 

This generation seems to be very good at integer performance, and of course very good at using special instruction sets like AVX-512. We saw uplifts compared to the past generation that are coming purely from an architectural improvement.

One thing Intel has certainly got really good at is milking every last drop from the 14nm manufacturing process.  Intel has the 14nm process licked, they have it licked so good they really are squeezing a lot of clock cycles from the process.  Meaning, they can ramp the clock speed up pretty high.  Sure, it gobbles power inefficiently to do it, but they can achieve very high clock frequencies.  Those clock frequencies are what translate to improved performance as well.  It costs power and thermals, but they have achieved a lot out of this process node.

The problem though, to target the power and thermal limits they needed to, cores were sacrificed with this architecture.  It’s a great architecture, it just was never meant for 14nm desktop CPUs.  Intel has done great with what they have to work with, but it does have its limits.  That limit is when it comes to floating-point performance and multi-threading performance. 

Quite simply, AMD offers more options in the multi-core arena.  The Ryzen 9 5900X at the same price gives you 4 more cores and 8 more threads.  The Ryzen 9 5950X gives you double the cores and threads.  Intel just doesn’t have an answer for that this generation.  Therefore, when it comes to workloads that benefit from more cores/threads, AMD has the advantage.

Therefore, deciding where these CPUs fit, depends on your needs, and your workloads.  The Intel Core i9-11900K is a fine gaming CPU.  It has all the cores and threads you need for gaming.  You don’t need more than 8c/16t setup to game in today’s games. The first problem is though, you can get this core/thread count setup from AMD for less money. The i9-11900K is priced to compete with the Ryzen 9 5900X, yet the Ryzen 7 5800X is the performance comparison. 

The other problem comes if you want to do more than just gaming, or gaming plus other tasks at the same time, like streaming.  If you render video, transcode video, edit in software like Premier, or render 3D, then you just can’t beat something like the Ryzen 9 5900X at the same price.  But, if you are just gaming, if that’s all you do, then it’s fine if a bit expensive.

The Final Points

At the end of the day, one does have to question the future of the CPU platform.  It is no secret that Intel is hard at work on the next generation after Rocket Lake, called Alder Lake, and we may see it sooner than we realize.  Rumors point to the end of this year, if not beginning of next year at the latest.  This next generation is said to take a huge step forward in a lot of areas.  What this means though, is that current generation motherboards, chipsets, socket layouts, and CPUs will be incompatible with the upcoming next generation.  It will require new motherboards, new chipsets, a new socket, new CPUs and maybe even new RAM. 

That means Rocket Lake is kind of at the end of a cycle.  It’s the last hoorah before the game really starts.  If you buy into this ecosystem now, you are most likely (though unconfirmed) at a dead stop, an end-of-the-road type of scenario.  That might not be a bad thing, if that’s all you need then that’s all you need.  But if you are looking for forward upgradability, it may not work out. 

So the question is what do you do?  Well, if you are upgrading from something very old, generations past, Haswell maybe? Rocket Lake and specifically the Core i9-11900K will provide a decent boost in performance across the board.  But if you are only one or two generations back, or have something from AMD in the last few years, it might be better to hold off and see what Intel has up its sleeve next toward the end of the year.

BTW, stay tuned, we will have our Intel Core i5-11600K CPU Review published later this week, you don’t want to miss it.

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Brent Justicehttps://www.thefpsreview.com
Former managing editor of GPUs at HardOCP for 18 years, Brent Justice has been reviewing computer components since the late 90s, educated in the art and method of the computer hardware review, he brings experience, knowledge, and hands-on testing with a gamer-oriented and hardware enthusiast perspective. You can follow him on Twitter - @Brent_Justice You can sub to his YouTube channel - Justice Gaming https://www.youtube.com/c/JusticeGamingChannel You can check out his computer builds on KIT - @BrentJustice https://kit.co/BrentJustice

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