Intel made some significant changes to the Coffee Lake architecture in order to keep its Core CPUs competitive with AMD's Ryzen line-up. Beyond giving the Core i7 family six Hyper-Threaded cores, Intel also narrowed the clock rate difference between premium K-series chips and the more mainstream models. Core i7-8700K does boast a 500 MHz base frequency advantage over Core i7-8700. But that gap shrinks as Turbo Boost is enabled and more cores spin up. By the time four cores are active, both chips should sustain 4.4 GHz.
Unfortunately, the decision to bundle Core i7-8700 with an all-aluminum heat sink means that you may not always get the chip's most aggressive Turbo Boost frequencies under taxing workloads. You'd assume that a CPU with 50% more cores would also dissipate more heat than its predecessor. And yet Intel didn't think to include a cooling solution with enough thermal headroom to realize its peak performance. This is especially perplexing given the praise AMD received for packaging its processors with beefy heat sinks.
Most of the time, though, Core i7-8700 does deliver an experience that closely mirrors the flagship -8700K at its stock settings. Check out the charts below, which plot gaming performance with average frame rates and a geometric mean of the 99th percentile frame times (a good indicator of smoothness) converted into a frame-per-second measurement. We also have price-to-performance charts that get split up to include the CPUs-only, plus extra platform costs. For the models that don't come with a bundled cooler, we add $25 for a basic heat sink. We also add $20 if overclocking requires a more expensive motherboard (as is the case for Z370).
For those similar performance results, expect to spend about $50 less on a Core i7-8700. If you game at higher resolutions, the differences between CPUs shrink even more. And the -8700 looks a lot like a stock -8700K through most of our other application benchmarks, too.
Intel doesn't have a great track record for building backward compatibility into its platforms, so you are on the hook for a new 300-series motherboard, regardless of what you're stepping up from. But unless specific features of the Z370 chipset catch your eye, Core i7-8700 offers the exact same performance if you drop it onto a cheaper B-series board. That should save a few extra dollars...
...which you'll want to turn around and spend on a better thermal solution than what Intel includes with its -8700. That heat sink and fan combination is obviously a poor fit, and better thermal paste won't fix the issue. By stepping up to a sufficient third-party cooler, you won't have to worry about artificially clipping the -8700's top-end Turbo Boost bins due to overheating. A six-core, Hyper-Threaded CPU rated for 65W sounds great for performance-sensitive applications in small form factors. But power consumption definitely spikes higher under load. Apparently, many low-profile coolers lack the headroom for Core i7-8700, so do your homework before replacing the stock sink in a space-constrained environment.
In the past, we recommended Ryzen 7 2700X over Intel's Core i7-8700K due to AMD's lower price point, similar gaming performance, bundled cooler, and better benchmark results in threaded applications. We expected Core i7-8700's comparable performance and pricing advantage to level the field. However, Intel's sub-standard cooling solution means we can't recommend the -8700 without a suitable replacement, adding to the CPU's overall cost.
AMD's Ryzen 7 2700 is also worth considering in this category. Its unlocked ratio multiplier and overclocking support on B-series motherboards yields a more attractive value story than what we get from Core i7-8700. Of course, if you need integrated graphics with your high-end CPU, Intel is the only game in town. And if you're looking for the best blend of price and performance for gaming specifically, the Core i5-8400 is still a favorite.
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