The new Core i5-7600K is identical to the Core i7-7700K in all save a couple of key areas. The L3 cache amount falls from 8MB to 6MB, and while it has an identical TDP of 91W, it has a base clock of 3.8GHz and a turbo frequency of 4.2GHz. These frequencies are 400MHz and 300MHz slower than those of the Core i7-7700K respectively, although stock speeds are largely irrelevant when you have an unlocked K-series CPU.
However, this clock speed is the key area where the 7600K differs from its predecessor – the Core i5-6600K – with a 300MHz base clock advantage and a further 300MHz turbo boost bonus as well. The other difference is, of course, the lack of Hyper-Threading support. The Core i5-7600K is a quadcore CPU that can handle four simultaneous threads, compared to eight threads for the Hyper-Threaded Core i7. The CPU also features Intel’s new 4K video engine, which can encode and decode 4K video in hardware, so playback is much smoother than on Skylake CPUs, and power consumption is lower, although that’s mainly a benefit for laptop users.
Interestingly, Intel has added an unlocked Core i3 chip to the fray as well – the Core i3-7350K. Unlike the Pentium G3258 (and the Core i5-7600K), the new dual-core budget unlocked CPU supports Hyper-Threading, so it can handle four simultaneous threads, potentially making it much more competitive than previous Core i3 chips across the board. Quite how much its might impact on Core i5-7600K sales remains to be seen; we haven’t had our mitts on it yet as the CPU doesn’t launch until the end of January. However, if you’re on a tight budget, it might be worth waiting until we’ve reviewed the new Core i3 CPU before you fork out for the Core i5-7600K.
Overclocking the Core i5-7600K has so far been very rewarding, and a few people in the industry have told us about similar experiences too, which is great news. Our Core i5-7600K sample was a great overclocker. We reached 5.1GHz using a vcore of just 1.38V and it required just 1.21V to hit 4.9GHz. That’s one of the best results we’ve seen for a long time, and it should be easily tamed by a good air cooler too.
The extra clock speed over the Core i5-6600K helped the Kaby Lake CPU to a reasonable advantage at stock speed, with a system score of 111,426 compared to 103,041, which increased to 132,685 and 125,926 when overclocked, with the Core i5-7600K again enjoying a clock speed advantage. There were similar gains in Cinebench R15 and in Ashes of the Singularity’s DirectX12 CPU benchmark, although this lead tailed off once both CPUs were overclocked. Also, the Core i7-7700K has a notable lead in the former test, showing a potential performance advantage in DirectX 12 games. There was also very little different in power consumption at stock speed. When overclocked, though, the slightly higher voltage and frequency obtained by the Core i5-7600K saw it draw slightly more power than the older Skylake CPU.
While there’s not much benefit over the Core i5-6600K in terms of clock-for-clock performance, the Core i5-7600K appears to be a much better overclocker than its predecessor. It can overclock further or require less voltage at the same overclock, which means it runs cooler too. It won’t make for much of an upgrade from a Core i5-6600K, but it’s currently the CPU to buy if you want the best value quad-core processor.