Intel Core i7-4790K Devil's Canyon CPU Review. Intel's brisk production schedule should see the new 14nrn Broadwell architecture arrive by Christmas, but that doesn't mean Haswell is out of tricks. To tide us over until the next generation arrives, Intel has released a new spin on the Haswell design, codenamed Devil's Canyon, that squeezes more performance from the hardware.
This has been achieved not through complex re-engineering, but by simply switching to a new thermal interface material - that is, the stuff inside the chip that conducts heat away from the transistors and up to the heatsink. Thanks to the use of "next-generation" thermal material, the chips enjoy better heat dissipation than the original Haswell models, so they can run faster without overheating.
What this means in practice depends on whether you go for a Core LS or i7 processor. Intel has set the base clock of the Core i5-4690K at 3.5GHz, only 100MHz higher than that of its predecessor, the Core i5-4670K.
With the Core i7-4790K, however, the company has pulled out all the stops. Previously, the fastest Intel CPU on the market was the Core i7-4770K, which has a base speed of 3.5GHz; the i7-4790K takes the same design, but cranks it up to 4GHz. When it comes to single-core operations, Turbo Boost accelerates things further still, to an eyebrow-raising 4.4GHz.
It's no surprise that the new chip tears through benchmarks. Tested in Windows 8, with 8GB of RAM and a Samsung 840 Evo SSD, the Core i7-4790K achieved an Overall score of 1.27 - a huge 13% improvement on the i7-4770K, representing the highest score we've seen from any desktop chip. The single-threaded Media section of the test was particularly strong: here the Core i7-4790K scored 1.35.
Incredibly, the i7-4790K had yet more to give, since, like all K-class processors, Devil's Canyon chips come with unlocked Turbo multipliers. We configured our Core i7-4790K to clock itself up to 4.7GHz for single- and double-threaded tasks, and 4.6GHz for more demanding scenarios. At these speeds, it achieved an Overall score of 1.31 with a standard, low-profile Intel cooler.
However, there's a price to pay. Like the Core i7-4770K, the i7-4790K is expensive at £259, and unless you do a lot of heavy-duty, multithreaded computing, it's of questionable value. Also, it's worth noting that running at such speeds takes a lot of power. Flip over a Devil's Canyon chip and you'll see an extra crop of capacitors that regular Haswell processors lack. To keep these fed, the new chips have a thermal design power of 88W - slightly higher than their predecessors.
But so what? Devil's Canyon isn't aimed at the low-cost, low-power market; it's for enthusiasts and can't-get-enough workstation jockeys. For them, it delivers better performance than Intel's previous flagship. If you're looking for exceptional desktop performance, there's only one reason to consider holding off: with Intel wringing such speed from its 22nm architecture, who knows what may be possible with its forthcoming 14nm parts?
Features
New! 4.0 GHz base frequency
4 Cores, 8 Threads
Fully unlocked for performance tuning
Intel® Turbo Boost Technology 2.0
Intel® Hyper-Threading Technology
Intel® HD Graphics 4600 (1250 MHz)
Supports LGA 1150 socket
8 MB Intel® Smart Cache
2 channel DDR3-1600 memory support
16 PCI Express* 3.0 lanes
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