IPC Performance
Intel made some pretty big performance claims when it comes to the 8th-gen Core series, but with 50% more cores on the Core i5 and Core i7 parts, it isn't that bold for them to claim up to 25% more frames in games. That said, are these gains down to the extra cores or have some architectural improvements been made to increase IPC? Some sources have suggested up to a 10% increase in this departmnet, so let's look into that. What I've done is lock the 8700K and 7700K at 4.5 GHz in addition to disabling two of the 8700K's cores, essentially mimicking the configuration of the 7700K.
First up we have Cinebench R15 and as you can plainly see with four cores and eight threads clocked at 4.5 GHz, just like the 7700K, the 8700K delivers basically the same scores. It was actually a fraction slower in the multi-threaded test after reporting the three run average. As expected, that nearly 50% increase in score comes from a 50% increase in cores.
Testing with Corona we again see that the 7700K is slightly faster than the 8700K when they are both matched with the same core and thread count at 4.5 GHz. Again adding two more cores makes the 8700K almost 50% faster.
And finally power consumption, this is an interesting one. The 8700K does pack 50% more L3 cache to support those extra cores and this isn't something we can disable when turning those cores off. When comparing the four-core/eight-thread configurations, the 8700K does push system consumption 10% higher at the same clock speed. Then with the extra cores enabled, total system draw is increased by 33%.