The Intel Core i7-8700K marks the largest change in the company's lineup in over a decade. It finally brings more than four cores to the mainstream desktop CPU space, a change that has most certainly been provoked by AMD's Ryzen offerings which feature up to eight cores. A second reason is that new production process technologies (i.e. 10 nm) are difficult to ramp up, so there is no other way than to add more cores to improve things right now.

Our comprehensive testing shows that pairing Intel's incredible per-core performance with additional cores and HyperThreading makes for an unstoppable winning combination. Averaged over our CPU benchmarks, which look at both single-threaded and multi-threaded performance, the Core i7-8700K can gain 15% over the previous generation flagship, the i7-7700K. This increase is one of the biggest in the Intel desktop space that we've seen in a long time. Applications that are properly multi-threaded, like rendering, see even larger gains; up by nearly 50%. Despite having the same architecture, single-threaded tests run faster, too, due to a higher single-core boost frequency of 4.7 GHz, which is 200 MHz more than the 4.5 GHz the 7700K reached in that scenario.

With those numbers, AMD's Ryzen offerings are left behind in the dust; their biggest hurdles are single-threaded performance and clock frequencies, which just can't compete with Intel's. In some tests, AMD still has the upper hand thanks to its higher core-counts, but even in those tests, the differences are slim enough to make you wonder if it's worth trading a small multi-threaded win for a large single-threaded loss.

Another interesting effect is that the Core i7-8700K obsoletes most of Intel's lower-end HEDT lineup, at least everything below the 7820X. When you look at mixed workloads, the high clocks of Coffee Lake deliver performance that is neck to neck with the 7820X despite it having eight physical cores; single-threaded loads are almost always won by the 8700K, which leaves only highly parallel workstation tasks and rare cases where you need a ton of storage or IO connectivity (multi-GPU gaming is not one of them with SLI and CF losing more and more support) for the HEDT processors.

Gaming performance is almost identical to that of the 7700K, with the exception of Civilization VI, which processes AI turn calculations on additional CPU cores, freeing up capacity for higher FPS. All other games run just as fast, even at the extremely CPU-limited scenario of 720p. It seems that game developers will have to start utilizing more threads in their engines first before we can see tangible gains. Don't get me wrong, the 8700K is without any doubt the best processor for gaming you can buy; there is just nothing to gain when compared to the 7700K, making that upgrade path a side-grade. If you are on an older Sandy Bridge processor and are looking to upgrade, specifically for gaming, and are not budget-constrained, then the Core i7-8700K is the way to go.

Thanks to its unlocked multiplier, overclocking is a breeze and easy to do. In our testing, we reached 5 GHz without any problems, with 5.1 GHz in reach on 240 mm AIO watercooling. While 5 GHz was easy at near-stock voltage levels (= heat output barely increased), going beyond that magic number required increasingly more voltage, which not only increases power consumption, but also the processor's heat output. This makes air cooling impractical as the CPU would just get too hot and throttle down to lower frequencies, nullifying any gains from overclocking. At 5 GHz, the Core i7-8700K is just unbelievable in the performance it delivers, gaining another 10% performance on average in CPU tests. Games see 2-3%, not that much, so don't waste too much time on trying to figure out how to reach that last extra MHz.

The Core i7-8700K is currently listed online for $380, which is $40 more than the $340 that's asked for the i7-7700K - a very reasonable price bump considering the extra cores. At that price point, the 8700K offers excellent value, better than anything else near its price point (7700K, 7800X, and1700X). As mentioned before, when playing games, upgrading from a 7700K to the 8700K is not worth it. For everybody else, especially when upgrading from a several-generations-old processor, the 8700K is the best CPU money can buy. If you are a gamer on a budget, then you could consider the cheaper Coffee Lake processors, like the i5-8400 and i3-8350K, that provide almost identical framerates at lower cost; money that could go towards a faster graphics card.