Intel Core i9 9900K Review

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Intel Core i9 9900K Review

The former champion is no more. The Intel Core i9 9900K was the world's fastest gaming CPU when it first launched, followed by the 9900KS, which had the shortest runtime. The new Comet Lake CPUs offer more cores, higher clock speeds, and the same price: where is the 9900K now?

First and most obviously, the 9th generation Core processors introduced an 8-core part: the Core i9 9900K, an 8-core/16-thread design thanks to Hyper-Threading, moved to the top of the stack. It also comes with 16MB of shared L3 cache, which directly scales in size with the number of cores.

Next, Intel announced further optimizations to the 14nm process, naming the new variation 14nm++; Broadwell and Skylake used the original 14nm process, while Kaby Lake and Coffee Lake used 14nm+. Intel did not elaborate much on what has changed with 14nm++ compared to the original 14nm+, but claimed that it is now possible to have more cores with similar clock frequencies within the same power envelope. Interestingly, Intel did not mention anything about further improvements to the Comet Lake 10th generation chips, so we can only assume that the same 14nm++ design is being used. [For the first time since Devil's Canyon (i7-4790K update to Haswell), Intel used a soldered TIM (Thermal Interface Material) in its 9th generation CPUs. Previously, Intel used thermal paste between the CPU die and the heatspreader. Switching to solder improves thermal conductivity and heat dissipation, resulting in similar temperatures at lower or higher clock speeds.

The minimum guaranteed clock speed for the 9900K is 3.6 GHz and the maximum single-core clock speed is 5.0 GHz. Intel suspended official disclosure of turbo clock speeds for all cores in the 9th generation, I believe primarily because motherboard manufacturers were not fully complying with TDP values for enthusiast processors. As is still the case, Intel has sort of given up on this particular battle.

Having tested many previous generation CPUs, motherboards from ASRock, Asus, Gigabyte, MSI, and others tended to be a bit lax on TDP and multipliers, especially under heavy loads. Let's take a look at the MSI Z390 MEG Godlike (I simply call it "Meg") that I used for my 9th generation testbed.

The Meg allowed the 9900K to achieve 5.0 GHz on loads up to 3 cores, 4.8 GHz on 4-5 core loads, and 4.7 GHz on a fully loaded CPU. This is impressive, but in my tests with the NZXT Kraken X62 cooler, the CPU peaked at 85°C under y-cruncher and heavy AVX workloads, and consistently recorded 75°C under Cinebench 15 multithreading. Performance was excellent, but the X62 is a rugged cooler and system power consumption from the wall exceeded 250W under some workloads.

This is a symptom of the different power limiting (PL) Intel employs in its chips: at PL1, the CPU is essentially running at its base TDP, but in Turbo mode, the CPU has access to more power for a limited time before reaching PL2. At this time, more power is consumed, resulting in higher clock speeds to work with. [This illustrates the performance differences between different motherboards.

Intel basically gives motherboard manufacturers free reign when it comes to enthusiast CPUs and multipliers; AMD's Ryzen 7 2700X can draw nearly 150W of "stock" power on my X470 testbed. This is because I wouldn't expect to run an 8 core/16 thread CPU at 4.7GHz under AVX workloads while using a cooler rated at only 95W. You'll probably just get thermal throttling, but you'd better plan on buying a high-end cooler for the Core i9 9900K.

Here another difference between AMD and Intel CPUs comes into play: the Ryzen 7 3700X comes with a Wraith Prism cooler and sells for $275. Intel offers the same number of cores and threads in the Core i9 9900K, with about a 20% increase in clock speed (and a slight increase in instructions per clock (IPC)), but it still costs about $500 for the CPU alone and at least $100, if not more, for cooling. At least $50, if not more than $100, needs to be planned for cooling. The total cost of a real PC would be $250 to $300 higher. ...... But is it worth the price? That depends largely on what you do with your PC.

Since I'm a PC Gamer, I'll start with gaming performance. Intel has traditionally held a lead in gaming performance against AMD's new Ryzen processors. However, that is becoming increasingly irrelevant given that cheaper AMD and now Intel processors are able to match or surpass these gaming frame rates.

The good news is that if you have a 9900K on your current machine, there is no need to upgrade. Also, even though the core count game is moving forward in both the red and blue camps, it is unlikely to make a significant difference in the game for some time to come.

However, with the AMD Ryzen 9 3900X seemingly recently priced out and reports of a mid-year Ryzen refresh circulating and becoming increasingly plausible, the 9900K's multi-threaded performance is underwhelming for the money. 12-core, 24-thread AMD in the $400s chips available and soon to be installed on inexpensive B550 motherboards, it still offers competitive gaming performance.

If you connect a high-end GPU to an AMD rig and play games at 1080p or higher, you will find that there is little difference in gaming performance between it and the latest processors.

At that point, you have to ask yourself how much is the extra 2 frames per second worth? This is because you can provide a specific amount of money for how much you would have to pay to get those two frames.

The power and thermal aspects of the Core i9 9900K show the limitations of Intel's current 14nm process technology (14nm++ if you prefer), which are exacerbated by the release of Comet Lake. Indeed, the 9900K runs at a similar clock speed to the 8700K, with two additional CPU cores, but with higher power consumption. This is the same story for the 9900K to the 10900K.

Bring a decent cooler and don't expect much overclocking headroom. I was able to clock all 8 cores up to 5.1GHz, but only a 400MHz gain with only 0.05V added, and CPU temperatures exceeded 90°C. The AVX workload required a similar offset to be applied, and 4.9GHz at AVX (200MHz better than "stock") was similarly high temperatures.

As a value proposition, the Core i9 9900K was not exciting. Intel has typically charged more for performance advantages, as it did with the Pentium 4. It may be faster than competing Ryzen chips, but when you factor in high-resolution gaming on a decent GPU, the difference becomes almost negligible.

It is relatively lackluster in multithreaded workloads and has lost its advantage in games. It is now an outdated pile of silicon.

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