It takes a lot to improve on a processor. Hundreds of millions of dollars of R&D, in fact. Take the short-lived Broadwell CPU, released just a few months before Skylake: in essence it’s a die shrink of the Haswell architecture, but boy did it take Intel some time to get that one nailed. But then shrinking below 22nm is no laughing matter. It was Intel’s (and the world’s) first-ever consumer 14nm processor. That paved the way for Skylake and the i5-6600K, the new best gaming CPU in town.
Sklyake’s new architecture at 14nm provided a much needed 10% improvement on the last generation of processors while also supporting modern advancements with the Z170 chipset. It brought DDR4 support to the masses, improved USB and Thunderbolt support and swapped over from 8 PCIe 2.0 lanes on the chipset to 20 PCIe 3.0 lanes instead, for all of your M.2 storage needs.
Number Of Cores: 4
Base Clock Frequency: 3.5 GHz
Turbo Clock Frequency: 3.9 GHz
L3 Cache: 6MB
Thermal Design Power (TDP): 91W
PCI-Express 3.0 lanes: 16
Since the launch of Nehalem way back in 2009, the i5 processor lineup has been the absolute cornerstone of dependable gaming processors. And today, not a lot has changed. If you’re after one of the best all-rounders, Intel’s i5-6600K is definitely up there with the best of them. Much more reasonably priced than the audacious i7-6700K, this quad-core chip runs at a base frequency of 3.5 GHz, ramping up all the way to 3.9 GHz under turbo. Although this i5 has an almost identical spec to our previous favorite CPU, the Core i5-4690K, overall performance for this processor trumps its predecessor by up to 10% in rendering, archiving and other workstation simulated tasks.
That doesn’t sound like a lot, but if you’ve been coasting on an Intel i5-2500K for a few years, now might be the time to make a jump to a new CPU. You’ll be looking at around 30-40% improved performance at the very least. And that’s not including the real reason to upgrade: all the new features of the Z170 chipset.
So why not an i7? Well there’s two main factors, the first being the cost. If you’re lucky you might be able to net yourself one of the nifty i7-6700Ks for just under £300 or $410, but honestly that’s a hell of a jump from the i7-4790K more reasonable price. And secondly? The i7’s hyper-threading adds very little to overall gaming performance. For the money you’d be far better off spending more on your graphics card instead.
If you are interested in the idea of streaming your gameplay footage over Twitch, or rendering YouTube videos for the masses to see, hyper-threading will be more useful, but even then we still wouldn’t suggest you grab the i7-6700K (see below). Ultimately it’s just not the best value for money. And for the vast majority of us the thoroughbred specs of Intel’s i5 lineup will be more than enough to satisfy all of our gaming desires.
Overclocking the 6600K
The next question we’re sure you’re asking is: “why the K series?” Overclocking isn’t for everyone, but it’s all about that longevity. Three of four years from now you might find yourself beginning to struggle with game performance. Whether that’s with post-processing effects, CPU-based rendering, or computational tasks, it’s eventually going to happen, and when that time comes it certainly won’t hurt to have some extra oomph from overclocking.
Throughout the entirety of Intel’s processor range the “K/X” in the model designation indicates that the multiplier has been left unlocked. What this means is that by adding a little extra voltage you can successfully adjust the multiplier to achieve a far higher overall clock frequency than before. Take this i5-6600K. It comes clocked at standard at 3.9 GHz, or 3900 MHz—a multiplier of 39, alongside a base clock frequency of 100. A simple overclock would be to increase the multiplier to 43, this would provide you with an overall frequency of 4.3 GHz and improve your performance in game, as well as in other computational benchmarks.
There’s more to it than that, and there’s inevitably always going to be some danger when it comes to increasing the amount of voltage going into your CPU. We’ll let Asus show you how it’s done here (don’t worry, though: the basic principles of overclocking haven’t changed much since Sandy Bridge).
In our testing we managed to get a maximum 4.8 GHz out of our Intel Core i5-6600K, with 1.4v amping into the VCore. For an everyday overclock we would advise you stick to something more comfortable like 4.4-4.6 GHz. It shouldn’t push your CPU too hard, and in some cases you might not even need to adjust the voltage, depending on how lucky you get in the silicon lottery.
Performance versus price
If you have no intention of overclocking, you won’t be much worse off immediately by opting for the i5-6600 instead. What matters here is the number of cores, and although there are definitely games out there that can make use of that additional processing power, they’re very few and far between. In fact if you’re looking to overclock anything, boosting your GPU by 5-10 percent will actually gain you far more frames per second in game than anything you ever do to your CPU.
As far as gaming performance goes, Intel’s i5-6600K is a strong contender. In our benchmarks we found this mighty quad-core provided little to no bottleneck in typically simple AAA titles. More CPU intensive games such as Creative Assembly’s Total War franchise benefited the most from additional clock frequency, more threads/cores, but it wasn’t enough to cause us any major worry, as most of this was down to post-processing, and the colossal number of assets being rendered and thrown around on screen.
Ultimately the i5-6600K’s biggest advantage came down to that Z170 chipset. Better support for M.2/U.2 PCIe storage, better USB support, overall lower power consumption, and that 10 percent improvement in computational tasks. In the vast majority of games can match up to either of the two big boys in our testing no sweat. For those reasons alone it’s our gaming CPU of choice.