Introduction

Intel introduced its 9th generation Core processor family with much fanfare earlier this month. The company increased core counts for a second time in the past couple of years, but this time, only bolstered its expensive Core i7 and new Core i9 mainstream-desktop SKUs with more cores. AMD managed to close the gap between its first Ryzen processors and Intel's 8th gen "Coffee Lake" processors with its new 2nd-gen Ryzen 2000-series. Had Intel stuck to the same 6-core die and incrementally updated it with features, such as a soldered IHS and higher clocks, it would have played into AMD's game, which was probably waiting with higher-clocked SKUs based on its 8-core "Pinnacle Ridge" die. Intel knew the only way out was to build a new 8-core die.

Upon its completion, Intel's product managers may have discovered that a fully unlocked "Coffee Lake Refresh" die is also much faster than the Core i7-8700K to be sold at its price-point, owing to 33% more cores and L3 cache. Intel hence decided to monetize it at a higher price point of $500, with the Core i9-9900K. It now needed something to sell at $350–$400 that's reasonably faster than the i7-8700K. Configuring the die as a 6-core/12-thread wouldn't have made the cut since the underlying micro-architecture is the same. Intel's answer came in the form of the Core i7-9700K, which is 8-core/8-thread and has just 12 MB of L3 cache. In a way, it has double the muscle of Core i5 quad-core processors from 2016, which are 4-core/4-thread with 6 MB of L3 cache. Despite the lack of HyperThreading, Intel hopes that the two additional physical cores will make the chip faster than the i7-8700K. Higher clock speeds, up to 4.9 GHz Boost, also contribute to this design effort.


The Core i7-9700K is designed to replace the i7-8700K from the product stack, at around $400. This 8-core chip is the first Core i7 product from Intel to lack HyperThreading. Intel has also reduced the L3 cache amount from 16 MB to 12 MB, or 1.5 MB per core. Each of the eight cores can address the entire 12 MB of L3 cache. Base clock speed is a touch lower than with the i7-8700K, at 3.60 GHz vs. 3.70 GHz. The maximum Turbo Boost frequency, however, has increased to 4.90 GHz vs. 4.70 GHz, which should improve performance with less parallelized workloads. For the i7-9700K and i9-9900K, Intel is introducing soldered integrated heatspreaders, which could contribute to lower temperatures by improving heat transfer between the CPU die and metal heatspreader.

Intel is introducing the new Z390 Express chipset with those new processors. This premium chipset is positioned above the Z370 Express and comes with higher CPU VRM requirements to ensure the highest possible overclocking headroom for the new 8-core processors. Also on tap is a newer integrated USB 3.1 controller. It also helps people identify motherboards that are guaranteed to support 9th generation Core processors out of the box. All other Intel 300-series chipsets for LGA1151 client, including H310, B360, H370, and Z370, support these processors, but require BIOS updates.

In this review, we take a close look at a retail Core i7-9700K processor supplied to us by our friends at Caseking.de, one of Europe's leading online retailers of PC components.

A Closer Look

Our sample arrived in a chip-only tray package, so we used stock images for the packaging. Unlike the Core i9-9900K which comes with a wacky and completely unnecessary retail packaging, the i7-9700K is less frustrating to unpack. You get the familiar slimline paperboard box the i7-8700K ships in. In it, you'll find the processor, some literature, and the case badge.


The Core i7-9700K looks like just any other LGA115x-class mainstream desktop processor made in the past nine years. The processor is compatible with LGA1151 motherboards based on the Intel 300-series chipset.


For its mainstream-desktop processors, Intel has maintained a largely uniform package size for the past decade, dating all the way back to Core "Lynnfield" LGA 1156. The cooler mount-hole spacing hasn't changed. You will be spoiled for choice when choosing a compatible cooler; however, make sure it can cope with at least 95 W TDP. Certain low-profile coolers designed for 65 W or 45 W TDP chips are not recommended.

The Coffee Lake Refresh Silicon

At the heart of the Core i7-9700K is the new 8-core "Coffee Lake Refresh" silicon built on the same 14 nm++ process as the 8th generation Core processors. The die is laid out in the same essential design as "Skylake," with two rows of CPU cores sandwiching the ringbus, each core with a dedicated L2 cache and 2 MB slice of the L3 cache. Each core can address the entire 16 MB of L3 cache on the die. For the Core i9-9900K, all L3 cache slices are fully unlocked. For the i7-9700K, however, each core is configured with a 1.5 MB slice, which adds up to 12 MB. The 6-core i5-9600K is based on a die with only 6 cores physically available, and configured with 1.5 MB slices that add up to 9 MB. Intel is starting to reach the core-count barrier beyond which the ringbus has to be junked in favor of Mesh Interconnect tiles, or it will suffer the detrimental effects of ringbus latencies.


The ringbus is town square and the primary intra-silicon communications fabric. It binds all eight cores with the uncore components (integrated northbridge, memory controller, PCIe root-complex, etc.) and the iGPU. Intel has improved the integrated memory controller to now support up to 128 GB of dual-channel DDR4 memory. For most users this is meaningless, but if you plan on building a future-proof machine that will last the next seven years or so, you never know when you'll need more than 64 GB of RAM.


Much of the processor's uncore components are clumped into the System Agent, which contains the memory controller, PCI-Express gen 3.0 root-complex, DMI interface, and memory PHY. On the other end of the ringbus is the Gen 9.5 integrated graphics, which has practically been carried over for the past three generations, featuring 24 execution units in the GT2 trim. At best, Intel may give it some software improvements that leverage the additional CPU power on tap. The iGPU is still branded under Intel's Graphics UHD family. Don't expect to play PUBG at 4K on this; the "UHD" moniker only indicates that the IGP can handle 4K Ultra HD displays, features modern connectivity options, such as DP 1.4 and HDMI 2.0, and can playback 4K video in new formats with 10-bpc color and HDR10/Dolby Vision standards.


Between "Skylake" and "Coffee Lake," Intel turned its R&D efforts toward refining the 14 nm process. It met with success on "Kaby Lake," and owing to its significantly higher clock speeds, "Kaby Lake" was able to provide higher performance than "Skylake." With "Coffee Lake," the nominal clock speeds look low, but Turbo Boost frequencies are higher than "Kaby Lake," and refinements in the process allow the chip to sustain elevated boost-clock states better. Between "Coffee Lake" (8th gen) and "Coffee Lake Refresh" (9th gen), the CPU core design has not changed. Intel did implement certain silicon-level fixes against security vulnerabilities.


A long overdue innovation Intel introduced with the 9th generation is STIM, or soldered thermal interface material, which is Intel-speak for a soldered IHS (integrated heatspreader). Intel has been using thermal paste as the TIM between the CPU die and IHS for the past several generations, and in response to AMD implementing the soldered IHS across its entire lineup, Intel implemented it on at least the 8-core i9-9900K and i7-9700K. Some of the cheaper parts could continue to use thermal paste.

The Intel Z390 Express Chipset

As we mentioned earlier, the only reason Intel appears to have launched the Z390 Express chipset while its existing Z370 chipset supports this processor through BIOS updates is because there could be motherboards with assured out-of-the-box support for 9th generation Core processors. Intel has also reportedly raised the CPU VRM requirements for the Z390, so motherboards based on it can maximize the overclocking headroom of the i9-9900K and i7-9700K. You can still overclock these chips with Z370. In terms of connectivity, the only thing that sets the Z390 apart from the Z370 is integrated 10 Gbps USB 3.1 and an external WLAN controller for 802.11ac.