Intel upped the core count on its mainstream processors with Coffee Lake. This had to happen, and frankly, would have been unthinkable if Team Blue introduced yet another generation of quad-core chips in light of how AMD has redrawn the battle lines with Ryzen and Threadripper.
And, so, here we are.
The Intel Core i7-8700K is at the top of the Coffee Lake product stack, with six cores, 12 threads and higher frequencies than any of AMD’s Ryzen processors. After using this CPU for a week, 2017’s mainstream flagship is everything we’ve asked for from Intel, with otherworldly gaming performance and hyperthreading numbers that put Ryzen in its place. It can even overclock like a champ.
Pricing and availability
Priced at $359 (about £270, AU$460), the Intel Core i7-8700K takes on AMD’s best Ryzen 7 processors including the $399 (£319, AU$499) 1700X and $499 (£399, AU$649) 1800X.
Even if this CPU has two fewer cores than its Red-colored rivals, the 8700K pulls ahead with higher base and boost clocks 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 i7-7800X hexa-core Skylake X chip might come close in price at $379 (£349, AU$495), but those X299 motherboards will cost a bit more than the new Z370 chipset. And, if you’re thinking about moving on up to Coffee Lake Refresh, you’ll definitely have to pony up for a new motherboards, as the older Z270 platforms don’t support the latest generation’s higher power delivery demands.
While we’re adding up all the extra costs, bumping up the core count has resulted in a small price premium. Its predecessor, the Kaby Lake Intel Core i7-7700K, was a 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.
However, the Z370 isn’t actually much of an improvement over last-gen’s Z270 chipset. It still only supports dual-channel memory and, out of the 40 available PCIe lanes, only 16 are directly connected to the processor. The other 24 PCIe lanes share a single DMI 3.0 connection to the processor – which means you can only squeeze out the full potential of two GPUs – or one graphics card 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.
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
Obviously, with a core count increase comes the inevitable rise in power consumption. However, we weren’t expecting the Intel Core i7-8700K to be twice as power hungry as its Kaby Lake predecessors. Still, at idle, the 6-core chip sips electricity at an average of five wats, way less than the 12 watts the AMD Ryzen 1700X gulps, so Intel hasn’t completely abandoned energy efficiency.
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.
At the end of the day, the Intel Core i7-8700K stays relatively cool, maxing out at just 76 degrees, while operating normally and comfortably under a Thermaltake triple radiator as its cooling blanket. The only time it got a bit hot under the covers was when we overclocked the processor to that 5.1GHz mark, where it reached a peak temperature of 87 degrees.
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.
from TechRadar - Technology Reviews http://www.techradar.com/reviews/intel-core-i7-8700k