Intel Core i9-9900K 9th Gen CPU Review: Fastest Gaming Processor Ever

Hardware-Based Security Fixes, Architecture & Test Setup

Much like the Cascade and Whiskey Lake processors we recently covered, Intel's Coffee Lake refresh comes with hardware-based mitigations for the Meltdown and L1TF (Foreshadow) vulnerabilities. Current Spectre and Meltdown mitigations, which Intel delivers via software and microcode patches, can reduce performance by up to 10% on newer CPUs, with older hardware suffering even larger losses. The new mitigations, baked directly into the silicon, should reduce or even eliminate the performance impact for a few vulnerabilities.

As we're learning, it may take several processor generations before the fixes for all vulnerabilities are applied at a silicon level. Intel's ninth-gen CPUs do still need a combination of microcode and operating system patches. But at least Meltdown and L1TF Foreshadow are patched fully in hardware.

Architecture

Although we don't have much new information about Coffee Lake refresh architectural changes, David Schoor at WikiChip says the new chips use a familiar ring bus, an internal high-speed pathway connecting the cores and cache.

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This stands in contrast to the mesh architecture (deep dive here) that Intel uses on its high-end desktop models, including the eight-core Core i7-7820X. We've found that the mesh architecture has a negative impact on some desktop applications, including games, which Intel acknowledges. The mesh architecture was designed to increase scalability as it expands to higher core counts in the Xeon family.

Overclocking, Rounds One and Two

We tapped Corsair's H115i v2 to test our Core i9-9900K sample in the U.S. lab. This liquid cooler afforded enough headroom to sustain a 5.0 GHz overclock with a 1.33V Vcore and a Load Line Calibration 4 setting. It kept the chip at a steady 85°C during extended non-AVX stress tests. Folding in AVX instructions did, unfortunately, overwhelm the all-in-one. To reign in the thermal output, we set the AVX offset to -2, meaning the chip ran at 4.8 GHz during AVX-optimized workloads and 5.0 GHz in the absence of AVX instructions. We maintained a temperature of 95°C during three hours of Prime95 using those settings.

To model real-world settings attainable by enthusiasts with closed-loop liquid coolers, we applied the -2 AVX offset for our 5.0 GHz overclock in the gaming, office and productivity, and rendering tests.

We did not use an offset for the workstation graphics, compute, power consumption, and temperatures sections.

MEG Z390 Godlike

We're using MSI's MEG Z390 Godlike as our test platform for all Intel processors. This pricey board retails for $600, but has the power delivery subsystem to support aggressive overclocking.

The MSI MEG Z390 Godlike sits at the top of MSI's motherboard hierarchy. It has a decked-out 18-phase power delivery subsystem that's designed to squeeze every drop of performance out of Intel's new processors. It also comes with a few nifty accessories like an M.2 PCIe riser card and an HDMI streaming card.

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