Intel Core i7-8700K And Core i5-8400 Review: Coffee Lake - More Cores, Performance And Value

Intel Core i7-8700K And i5-8400 - The Verdict

Performance Summary: The Intel Coffee Lake-based Core i7-8700K and Core i5-8400 both performed well throughout our testing. The additional pair of cores help propel them well ahead of their previous-generation counterparts in multi-threaded benchmarks and their higher-clocks and use of Intel’s latest-generation processor cores also help single-thread performance. The 6-core/12-thread Core i7-8700K offered the best single-threaded performance we have seen to-date and its multi-threaded performance is roughly on-par with the 8-core/16-thread Ryzen 7 1800X and 1700X processors. And the Core i5-8400 managed to outpace the Core i7-7700K on a couple of occasions. Power consumption – especially at idle – was nice and low and 5GHz overclocks with decent cooling should now be a regularity with a bit of tweaking.

coffee lake angle
Intel Core i7-8700K And Core i5-8400 Processors -- Find Them At Amazon

Although they are not based on a totally new architecture, the design choices Intel made with Coffee Lake and its 8th Generation Core processors completely re-shape the company’s mainstream CPU line-up and bring the heat to AMD’s Ryzen 3/5/7. Here is a breakdown of how the 8th Generation Core processors series stacks up:

coffee lake chart
Intel 8th Generation Core Series Processor Line-Up

For $359, the Core i7-8700K competes well against 8-core Ryzen 7 series processors in multi-threaded workloads thanks to its higher frequencies, but it does so while also offering markedly better single-threaded performance and lower idle power. And versus its previous-gen counterpart, the Core i7-7700K, there is no comparison – the Core i7-8700K is faster all-around, for a similar introductory price. All things considered, the Core i7-8700K makes a compelling case for itself – this is one heck of a nice processor.

Though it doesn’t support HyperThreading, the Core i5-8400 also offers multi-threaded performance in a completely different league versus previous-gen quad-core Core i5 products, thanks to its 6-core configuration. In fact, the $182 Core i5-8400 even managed to overtake the Core i7-7700K in a couple of spots. Its multi-threaded performance isn’t on par with 6-core/12-thread Ryzen processors, but performance is still strong in its segment.

We really like where Intel is going with the first 8th Generation Core series processors – more cores and more performance, without breaking the bank. That's good stuff in our book. If you were considering a desktop CPU upgrade for a mainstream system, your decision may have just gotten a whole lot harder.


 hot  not
  • Strong Multi-Thread Performance
  • Killer Single-Thread Performance
  • Relatively Low Power
  • High Overclocks
  • Requires New Motherboards, Despite Using LGA1151 Socket
  • Not All Unlocked

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