Intel Core i7-4790K (Devil's Canyon) Review

Overclocking

With the Core i7-4770K reaching 4.8GHz with relative ease on good Z97 motherboards, we aimed for similar with the Core i7-4790K. Sadly, at 1.28V - our usual input for stability using a x48 multiplier, things went flaky as soon as we hit benchmarks. Over the next hour or two we gradually upped this to 1.33V, which eventually sorted things out and amazingly the temperatures were below 85°C under load. Our older Haswell CPU would be melting at these settings but unfortunately, 4.9GHz still wasn't achievable, even pushing the vcore to 1.4V, although it did boot into Windows.

Performance Analysis

There's little doubt the Core i7-4790K is faster than its predecessor and a pretty quick CPU in its own right too. It's the first to top 4,000 points in our video encoding benchmark at stock speed and was way ahead in the image editing test too, topping the charts in both benchmarks. Our multi-tasking test saw it fall a bit behind but we're aware that this can favour some motherboards over others depending on their CPU configuration and as we used quite a few different models overall, we can't read too much into the lackluster score here. Overall, the score of 2,654 was over 200 points clear of the Core i7-4770K and over 400 points - equivalent to 20 percent faster than the 2600K.

With such a huge clock speed advantage over its LGA1155 and LGA1150 compatriots, it was no surprise to see the Core i7-4790K topping our game benchmarks too. In fact in the The Elder Scrolls: Skyrim it was as fast as the Core i7-3770K at 4.8GHz, which is quite an achievement. it couldn't quite pull off the same feat in the Shogun 2: Total War CPU Test, but it still topped the chart at stock speed.


We've included Cinebench R11.5 and R15 as we're currently transitioning from one to the other. However, it's also interesting to see just how the new Core i7 fits in with some of the much older CPUs. For example, it's twice as fast as a Core i7-920. There's also some fairly significant gaps between it and the Core i7-4770K and 3770K, with its score of 9.60 eclipsing them at 8.12 and 7.91 respectively.

We'll be adding to the Cinebench R15 graph from now on and for the moment we only have overclocked numbers for the Haswell Core i7 CPUs. However, there's a pretty big leap from the Core i7-4770K, although not quite as large as that in R11.5 - just 882 compared to 822, a 7 percent gain. Power consumption numbers are again to be taken with a pinch of salt here as these are the numbers from our original Core i7-4770K review which used a different motherboard.

However, there's no big surprises here and even with over 1.3V going through the CPU at 4.8GHz, it's not a million miles away from the older Haswell CPU at 4.7GHz. In our recent Z97 motherboard reviews, we also managed to push our Core i7-4770K to 4.8GHz and here it usually required less than 1.28V - the highest power consumption was 194W and the lowest 180W.



So what does overclocking bring performance wise? Well, 4.8GHz isn't as high as we'd hoped given the stock frequency is 4GHz but it was enough to make some serious headway in the image editing test and secure the top LGA1150 result too. It also topped the charts in The Elder Scrolls: Skyrim and edged out a lead in the Shogun 2: Total War CPU Test too. LGA2011 CPUs still have an edge where more cores are better so rendering in Cinebench sees the 4790K outdo the 4770K but unable to keep up with the likes of the Core i7-3930K even with the latter at stock speed.

Conclusion

So, what to make of the Core i7-4790K? Our sample doesn't overclock as well as we'd hoped - 5GHz on air is possibly a myth, certainly compared to Sandy Bridge standards, but then again, it's early days and we've only had hands on with a single press sample. It most definitely runs cooler than our in-house Core i7-4770K but also required a little more voltage to hit 4.8GHz. With water cooling, it's possible more voltage could improve things - after all, the new thermal interface material appears to be doing a better job so beefier cooling could come into play.

Performance-wise, there's little doubt that you should opt for the new CPU over the older 4770K. The latter is slower in the vast majority of our tests, sometimes by a sizable amount, although we should be clear that the Core i7-4790K is not a worthy upgrade from the older Haswell CPU. 3770K owners may want to consider things - there are big gains to be had in rendering as the Cinebench tests showed and there's some noticeable gains in our media benchmarks as well as our game tests but if you're not desperate then you could wait for Broadwell to arrive, hopefully in around six months or so.

Overall then, it's a solid if not spectacular entrance for the Core i7-4790K, although we'll have our eyes firmly on the Internet to see how the general masses fare with retail samples when it comes to overclocking. We'll be back soon with a review of the multiplier-unlocked Pentium, as well as the Core i5-4690K as soon as our sample arrives.