Multi-chip Intel Core i9-11900K Overclocking Review: Four Boards, Cryo Cooling

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Back in March, Intel unveiled its 11th generation of desktop processors codenamed Rocket Lake. In its lineup, the flagship desktop chip is the Core i9-11900K, with eight cores, sixteen threads, and a current selling price of $545 at Amazon. Along with obvious performance advantages that come with the flagship model, including higher turbo frequencies, Intel has put a lot of its latest technologies into Rocket Lake including Thermal Velocity Boost (TVB) and Adaptive Boost (ABT) - the idea here is to to give the best possible performance out of the box. In this article, we take four retail Intel Core i9-11900K processors and four premium Z590 motherboards, including the ASRock Z590 Taichi, the ASUS ROG Maximus XIII Hero, the GIGABYTE Z590 Aorus Master, and MSI MEG Z590 Ace, and overclocking them. Is overclocking worth it on Intel's Core i9-11900K? Let's find out.

The Core i9-11900K: Intel's Flagship Desktop Processor

Before launching in March, there was a lot of discussion about Rocket Lake's potential performance. On the one hand, it looked just like another 14nm design refresh such as Skylake. While this is somewhat true, the reality is that it provides an advancement incrementally in terms of Intel's research and design model; Rocket Lake is actually retrofitted its 10nm design onto 14nm, for multiple reasons, including CPU core frequency (it's higher on 14nm), cost (14nm is cheaper to manufacture), and peak thermal window. The last point has been another talking point as Rocket Lake runs warm. One of the reasons for this, outside of refinements and improvements to turbo frequencies and internal automatic overclocking technologies, is Intel's move to PCIe 4.0 which comes directly from the CPU. As we found out in our initial Core i7-11700K review (and verified on the Core i9 and Core i5 models), if you blast this chip with a strong AVX-512 workload, you can draw near 300 watts, however day-to-day running at half that is easily par for the course. 

While there are many options on Intel's 11th generation for desktop, including various Core i5, Core i7, and Core i9 processors, the current flagship in the line-up is the Core i9-11900K. The Intel Core i9-11900K features 8 cores and 16 threads. In terms of specifications and operating frequencies, the Core i9-11900K has a base frequency of 3.5 GHz, while it has a 'turbo' which tops out at 5.3 GHz. At present, Intel's interpretation of Turbo is rather complex and requires digesting in different ways than previously thought.

Intel Thermal Velocity Boost (TVB) Versus Adaptive Boost Technology (ABT)

As it stands, Intel's Core i9-11900K has five levels of automatic overclocking. This includes the base frequency at default settings, Turbo Boost 2.0 (TB2), Turbo Boost Max 3.0 (TBM3), Thermal Velocity Boost (TVB), and Adaptive Boost Technology (ABT).

In our launch day review of Intel's Core i9-11900K, Core i7-11700K, and Core i5-11600K processors, we analyzed all of the turbo variants. Focusing on the Core i9-11900K, which we will be overclocking and testing in this article, we can see below that the Thermal Velocity boost enabled two cores to operate at 5.3 GHz. In contrast, the remaining cores fluctuated between 5.1 GHz and 4.8 GHz with what Intel calls Adaptive Boost Technology (ABT).
 
Looking at the Turbo Boost 2.0 frequencies on the Core i9-11900K, every core will operate a 4.7 GHz when all cores are loaded. If there is power and thermal budget available to use, then it will attempt 4.8 GHz, then 4.9 GHz, and so forth. This is what we like to call a 'floating turbo' as it is influenced by thermal and power budgets, which means users with more aggressive CPU coolers are more likely to see higher performance than those using more modest forms of CPU cooling such as smaller air coolers. This is a very similar method and implementation to AMD's Precision Boost 2 technology, which was introduced in April 2018 with Zen+.

If Intel's Turbo Is So Good, Why Manually Overclock?

Back in the 'good old days' when overclocking a processor could yield a 30-50% improvement in core frequency, the truth today is that both Intel and AMD are understanding how to get the most from the silicon straight from the factory. This also includes motherboard vendors who also make adjustments in its own Multi-Core Enhancement (MCE) implementations, making them not worth much over the standard feature set. This makes manually overclocking more of a conundrum than ever before, with fewer gains than previous generations. 

Taking all the turbo boost technologies away from the equation and instead focusing on the base frequency, an overclock of 5.1 GHz all-cores on the Core i9-11900K over the 3.5 GHz base frequency equates to around 45%, which could be impressive if ABT wasn't involved. If using the Turbo Boost 2.0 (TB2) of 4.7 GHz all-cores, the same 5.1 GHz overclock on all-cores is around 8-9%, which is meager in comparison. This is beneficial for novice users that intend to run the processor without making any out-of-the-box adjustments. Still, there's very little headroom in the grand scheme of things for the true enthusiasts among us due to these implementations.

Pushing The Limits of Silicon

Similar to how people 'tune' car engines for maximum power and performance gains, many people within this industry use their skills and talent to push computer hardware to the limits. Usually tied to motherboard manufacturers for the most skilled overclockers, people such as HiCookie (GIGABYTE), and Kingp!n (EVGA), actually compete at a high level on the world stage at overclocking events over the year for world records, and in a lot of cases, bragging rights for their respective affiliations. 
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