Intel Core i7 4790K “Devil’s Canyon” Processor Review

Introduction & What’s New?

Intel released its Devil’s Canyon CPUs at the start of this month in time for this year’s Computex event. Sadly we were delayed in getting our sample of the Core i7 4790K, which means our review has come out a little late, but nevertheless we have Intel’s new flagship on the test bench today for a good thorough review. For those of you who don’t know about Devil’s Canyon, it is Intel’s internal codename for its new Haswell Refresh K series CPUs. Devil’s Canyon includes the Core i7 4790K and Core i5 4690K, both quad core parts based on Haswell Microarchitecture but with speed bumps and a few modifications. There isn’t that much to say specifically about the Core i7 4790K that wasn’t already noted in our Core i7 4770K review, because the microarchitecture is still Haswell. However, there are a few new features that Intel is bringing to the table with Devil’s Canyon that have specifically been done to appease Intel enthusiasts and overclockers. The Core i7 4790K is unique in the regard that Intel have listened to the feedback and concerns of its user base and tried to make specific modifications to eliminate or reduce those concerns.

The first major change comes with regards to the physical characteristics of the CPU. Intel has swapped out the thermal paste under the IHS for a better quality thermal paste which should allow for lower temperatures and better overclocking as a result. Intel have also added additional capacitors to the back of the CPU which they claim smooths power delivery to the CPU die, which again should enhance overclocking potential. Another change that Intel aren’t really marketing is the addition of support for Virtualization Technology for Directed I/O (VT-d) and Transactional Synchronization Extensions New Instructions (TSX-NI)

Intel hasn’t just tweaked the physical design of the CPU either – they’ve also pushed the CPU’s performance even further. For the first time Intel is shipping a consumer processor with a 4GHz clock speed, that’s a barrier AMD broke many years ago but Intel has always been fairly cautious with its clock speeds. The CPU goes even further than 4GHz with a 4.4GHz Turbo frequency, from my experiences on a number of Z97 motherboards this basically means your CPU will always be at 4.4GHz so that’s a significant jump up from anything Intel have ever offered before. Frequency bumps aside the core count, thread count, cache size, graphics and socket all remain the same. Devil’s Canyon CPUs will price match their predecessors on paper but at retailers you can expect to see the older Core i7 4770K and Core i5 4690K slightly cheaper to the tune of $10-50. I also just want to clear up a note about backwards compatibility. Intel’s Core i7 4790K, Core i5 4690K and other Haswell Refresh CPUs will theoretically work in all 8 and 9 series LGA 1150 motherboards. Some motherboard vendors will need to issue BIOS updates to enable this support but all motherboards should get this support because the sockets still have identical pin-outs and the CPU pin-out has not changed either.