Intel had to push the core count on its mainstream processors with Coffee Lake. This was inevitable, and frankly, would have been unthinkable had chip maker introduced yet another generation of quad-core CPUs in light of how AMD has redrawn the battle lines with Ryzen and Threadripper.
And, so, here we are.
The Intel Core i7-8700K leads the pack of a new generation of Coffee Lake-S desktop processors with six-cores, 12-threads and higher frequencies than any of AMD’s Ryzen 7 processors. After testing the processor for a week, the new flagship chip is everything we’ve ever wanted from Intel with stellar gaming experiences, hyper-threading performance that outpaces Ryzen and plenty of room for overclocking.
Base clock: 3.7Hz
Boost clock: 4.7GHz
L3 cache: 12MB
Pricing and availability
Priced at $359 (about £270, AU$460), the Intel Core i7-8700K aims to take on AMD’s best Ryzen 7 processors including the $399 (£319, AU$499) 1700X and $499 (£399, AU$649) 1800X.
Though this processor comes with two fewer cores than its rivals, the 8700K pulls ahead with higher base and boost frequencies of 3.7 and 4.7GHz, respectively.
A hexa-core mainstream processor is a big step forward for Intel, who previously placed anything with more than four-cores within its high-end-desktop (HEDT) E- and X-series ranges.
Speaking of which, Intel’s current six-core i7-7800X Skylake-X CPU might come super close in price at $379 (£349, AU$495), but those X299 motherboards come at a higher premium than the new Z370 standard. Unfortunately, if you’re thinking about moving on up to Coffee Lake-S, you’re definitely going to have to buy a new motherboard, as older the Z270 platforms don’t support latest generation’s higher power delivery demands.
While we’re tallying up the extra expenses, bumping up the core count has resulted in a small price increase. The Kaby Lake processor the 8700K replaces, the Intel Core i7-7700K, was a teensy bit more affordable at $349 (£299, AU$459).
Features and chipset
Intel worked some form of black magic to squeeze 18-cores into the tiny Intel Core i9-7980XE, and some of that witchcraft has found its way into the Intel Core i7-8700K. Despite packing in two more cores than we ever saw on Kaby Lake, the processor package hasn’t grown by a single millimeter.
While that’s impressive, it’s also slightly annoying that this new generation of CPUs still demands us to buy into a whole new motherboard.
Furthermore, the Z370 platform isn’t really that much of a step up from Z270. You still only have support for dual-channel memory and, out of the 40 available PCIe lanes, only 16 are directly connected to the CPU. The other 24 PCIe lanes share a single DMI 3.0 connection to the CPU, which means you can only squeeze out the full potential of two graphics cards – or one GPU and two M.2 NVMe SSDs.
Thankfully, Z370 does have a silver lining of adding official support for DDR4 2,666MHz memory – up from the 2,400MHz frequency seen on Z270 – and improved power delivery for some of the greatest overclocking we’ve seen on a mainstream processor.
Test system specs
GPU: Nvidia GTX 1080 Ti (11GB GDDR5X VRAM)
RAM: 32GB Vengeance LED DDR4 (3,200MHz)
Motherboard: Asus ROG Strix Z370-E Gaming
Power Supply: Corsiar RM850x
Storage: 512GB Samsung 960 Pro M.2 SSD (NVMe PCIe 3.0 x4)
Cooling: Thermaltake Floe Riing 360 TT Premium Edition
Case: Corsair Crystal Series 570X RGB
Operating system: Windows 10
The Core i7-8700K brings Intel’s multi-core performance up to and well above the high benchmark Ryzen has set this year.
This chip soundly overtook AMD’s competing Ryzen 7 1700X in Geekbench 4, with a score several thousands of points higher – by extension, this makes the previous-generation Intel Core i7-7700K’s multi-core numbers look like a joke.
What’s even more impressive is Intel’s latest part beat the pants off its predecessor in all our single-core tests, too.
All of this processing power also ends up helping the 8700K convert video as fast as some of the industry’s most overpowered CPUs, like the Intel Core i9-7980XE and AMD Ryzen Threadripper 1950X – though these aforementioned chips will still win any hyper-threading race through sheer brute force.
In terms of gaming performance, by our testing, you’re not going see a huge improvement. Compared to the Intel Core i7-7700K, the shiny new hexa-core successor increased frame rates across the board, with the greatest improvement seen in titles running at Full HD and Ultra quality settings.
Overclocking and heat
Of course, with a core count increase comes the inevitable bump in power consumption, but we weren’t expecting the 8700K to be twice as power energy-hungry compared to its rivals. Still, at idle, the hexa-core CPU sips electricity at an average of five-watts, far less than the 12-watts the AMD 1700X gulps, so Intel hasn’t completely thrown energy efficiency out the window.
On the flipside, the 8700K is more than happy to soak up extra current and push itself beyond its rated maximum 4.7GHz frequency.
We easily achieved a 5.0GHz frequency across all the cores just by giving the processor an extra 0.02 volts of juice, and only saw the maximum temperature jump to 85-degrees Celsius and 152.84 watts of power consumption. Another extra dab of juice allowed us to further clock up the Intel Core i7-8700K to 5.1GHz across all cores without significantly detrimental effects.
Pushing the six-cores to 5.2GHz unfortunately proved to be too unstable to even get Windows 10 to load properly. While this might seem disappointingly short from the 8700K’s maximum speed of 4.7GHz, we’re impressed with how little extra heat and power demands overclocking created.
Overall, the Intel 8700K stayed relatively cool, maxing out at only 76-degrees Celsius while operating normally and comfortably seated under a Thermaltake triple-radiator as its cooling blanket. The only time it got a little hot under the covers was when we overclocked the CPU to the aforementioned 5.1GHz, wherein it reached a peak temperature of 87-degrees Celsius.
Intel Core i7-8700K proves Team Blue is still the top dog in the processor world. Coffee Lake is a clear improvement over Kaby Lake with impressively higher single-core and multi-core numbers, and ever-so-slightly better gaming performance. What’s more, the staggering hyper-threading performance puts it well above AMD’s octo-core Ryzen processors and even into the realm of some high-end desktop (HEDT) parts.
The Intel 8700K gets a little hotter and more power hungry than we would like, but that was somewhat expected with the bump up in cores. What we didn’t expect as a pleasant surprise was the ease of overclocking the processor to 5.1GHz, not to mention the relatively low-impact of doing so.
The toughest pill to swallow out of all of this is having to get a new motherboard to even use Coffee Lake-S. But, if you’re willing to spend the money to upgrade both components, the Intel Core i7-8700K is the best mainstream processor on the market, and it comes with all the bragging rights of having the highest benchmark numbers in its class.