Exclusive: Testing Intel's Unreleased Core i9-9900KS

Core i9-9900KS IPC, Overclocking and Test Setup

R0 versus P0 Stepping IPC Testing

Intel has steadily added new hardware-based mitigations for many of the new vulnerabilities, like MSBDS, Fallout, and Meltdown, with new steppings of its die. Our Core i9-9900KS processor comes with the R0 stepping (Stepping 13), which stands in contrast to our -9900K model with the P0 stepping. These in-silicon fixes have been rumored to have some impact on IPC, so we ran a few quick tests.

We set a static 5 GHz clock rate and dialed memory to the respective processors' supported frequency for the following tests:

Image 1 of 3

As we can see, several workloads show some IPC regression, albeit mostly minor ones. It's important to remember that IPC can vary by workload, so dissimilar tasks may yield different outcomes. It's also possible that these regressions could stem from motherboard firmware that isn't fully optimized. We'll dive deeper on this topic in our full review. 

Intel Core i9-9900KS Overclocking

We tested the Core i9-9900KS at stock settings with both a Corsair H115i cooler and a custom watercooling loop with an EKWB Supremacy Evo waterblock paired with two 360mm radiators to remove thermal limitations from the equation. 

We turned the same amount of attention to the KS's 5.0 GHz boost as we have with our series of AMD Ryzen 3000 boost clock tests. We'll share detailed results of those tests in our full review, but suffice it to say the Core i9-9900KS consistently sustained a 5.0 GHz boost on all cores, regardless of workload, with these cooling solutions. The -9900KS certainly has one of the most aggressive Turbo Boost implementations we've ever seen, and it's effective. We'll also carve out the time to see how the processor handles with a beefy air cooler, so stay tuned. 

We saw little to no performance variation stemming from the different coolers at stock settings throughout the full breadth of our application testing suite. As such, we turned to the custom loop for our stock and overclocked gaming test results. 

We easily attained a 5.2 GHz overclock with the custom loop. We set vCore at 1.36V, tuned the memory to DDR4-3600, and adjusted Load Line Calibration on our MSI Z390 Godlike motherboard to Level 3. FCLK adjustments also seemed to help with stability, so we adjusted the setting to 1000 MHz. 

We think there is plenty of room for more overclocking action on our custom loop, and some room for tuning on the H115i AIO cooler. Rest assured that we'll include more in-depth overclocking testing in our full review.

You'll pay a pretty penny for the Core i9-9900KS, but your odds of getting a cherry chip are certainly improved. Overall, the Core i9-9900KS proved to be an easy overclocker, but as always, your mileage may vary. 

Core i9-9900KS Thermals

From our early analysis, watercooling is going to be a must with this processor. We registered temperatures in the 85-89C range during extended AVX stress tests at stock settings with the Corsair H115i cooler. However, it is noteworthy that the processor maintained a 5.0 GHz clock rate during those tests. Those stock temperatures dropped to the 60-64C range with our custom water cooling loop. After tuning to 5.2 GHz, temperatures hovered in the 77-81C range during an extended AVX stress test (custom loop).

Core i9-9900KS Power Consumption

Image 1 of 3

We tested power consumption with AIDA64 in both AVX and non-AVX flavors, and also with the y-cruncher benchmark that computes pi using a heavy multi-threaded AVX workload. As a general trend, we can see that the -9900KS consumes far less power at its stock 5.0 GHz than what we need to push the -9900K to similar levels of performance. That equates to less waste heat dumping into your case. 

A Note on Multi-Core Enhancement (MCE)

Intel's motherboard partners have infused their boards with predefined all-core boost profiles that go by many names, such as Multi-Core Enhancement (MCE) with ASUS motherboards and Enhanced Turbo with our MSI motherboard. These features are largely referred to as MCE, but the functionality remains the same: These settings essentially apply an all-core overclock to the processor that is defined by the maximum Turbo Boost bin supported by the processor. This setting modifies the CPU's clock rate and voltage to deliver higher performance, which is basically factory-sanctioned overclocking.

MSI turns this on by default in its BIOS, similar to most of its competition. Performance, power consumption, and heat are all affected, naturally. We manually disable this feature for our stock CPU testing to best reflect Intel's specifications. 

Test Methodology

It bears repeating: 

In the interest of time, we're not posting our entire test suite. This article serves as a preview of what you can expect from the -9900KS, but bear in mind that while our BIOS is listed as compatible with the KS, motherboard vendors tend to issue performance-boosting updates during NDA cycles. We're also testing with pre-production silicon, which could also leave out other possible improvements.  

We updated our test image to the latest version of Windows 10 available at the time of publication (18362.356). All of our test results come from the aforementioned operating system and include all publicly available security mitigations. Intel is currently impacted by Spectre, Spectre v4, Meltdown, Foreshadow, Spectre v3a, Lazy FPU, Spoiler, and MDS, while AMD is only impacted by Spectre and Spectre v4. 

All applications, drivers, and motherboard firmware revisions (including AMD's boost-fixing ABBA AGESA code) are up-to-date as of seven days prior to the publication date. The complete refresh of performance data has led to more of a constrained test pool than we're accustomed to, but rest assured that we'll have a broader selection of comparison processors with our full review. 

MSI 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 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.

Test System and Configuration

MORE: Best CPUs
MORE: Intel & AMD Processor Hierarchy
MORE: All CPUs Content