Product on Review: Core i5-6600K & Core i7-6700K
Street Price: £199 GBP / $243 USD + 269.99 GBP / $350 USD
The 6th generation of Intel’s Core architecture, codenamed ‘Skylake’, is the latest in a line of CPUs which began with the Nehalem microarchitecture in 2008. Since then Intel followed a ‘tick-tock’ development strategy - alternating smaller fabrication process nodes and large architectural revisions in each new release – which has been hugely successful in keeping them ahead of the game and the competition.
As the 6th generation Core architecture, Skylake is classed as a ‘tock’. Utilising the same 14nm fabrication process node as Broadwell, in Skylake Intel have taken what they’ve learned from a year of Broadwell and focussed on advancements in architecture to make the CPU both more power-efficient and powerful. Furthermore Skylake brings high-bandwidth DDR4 memory to mainstream computing, one year after Haswell-E brought it to the enthusiast and workstation segment.
It’s been clear for the past year that Broadwell’s release was delayed, perhaps due to problems with 14nm fabrication or some other factor. Last year the Devil’s Canyon Haswell refresh took the place of Broadwell performance SKUs, bringing performance benefits to underserved enthusiasts. Meanwhile most Broadwell designs have only made it into the mobile product stack, rolling out in laptops and All In One desktop models that took advantage of major steps forward in power efficiency (from moving to 14nm) and integrated graphics horsepower (thanks to advances in Intel HD and Iris Graphics).
Although Broadwell was important for mobile products due to the node shrink to 14nm production, especially all-in-one designs, desktop releases were minor. This was especially the case in the enthusiast segment, where the Core i7 5775C/R and Core i5 5675C/R focussed on the introduction of Iris Pro graphics to the mainstream and performance segments rather than raw speed and overclocking potential. Broadwell, it appears, is being rather hurriedly supplanted.
Skylake also comes with a new motherboard chipset, codenamed ‘Sunset Point’. This new 10-series chipset makes use of an LGA1151 socket, and as a consequence it’s clear that both Skylake and Sunset Point are incompatible with the previous motherboard and CPU generations respectively. This brings to an end the era of 8- and 9-series motherboards, but also ushers in new designs with features now set to be mandatory rather than optional extras.
In a departure from other generational releases Skylake’s is phased. Arriving today are only two SKUs – the Core i7 6700K and Core i5 6600K, models from the Performance and Mainstream line which cater primarily to overclocking enthusiasts thanks to the use of a fully unlocked multiplier. The timing coincides with the release of Windows 10, with Intel feeling that they need to provide compelling options for early adopters and college-goers who will upgrade their whole system on the launch of Microsoft’s new OS. Furthermore launching on the first day of GamesCom isn’t happy coincidence; Europe’s largest games convention has the audience that Intel needs to push these processors out of niche categories and into the hands of mainstream gamers looking for the next big thing.
Complementing the release of the Skylake overclocking SKUs is the release of Z170 motherboards through Intel’s partners ASUS, MSI, GIGABYTE et al. In contrast to mainstream ‘H-series’ design, ‘Z-series’ motherboards are capable of overclocking and generally feature far more robust power infrastructure and UEFI BIOS functionality. We’re reviewing two of these launch designs in separate articles you can read alongside this one.
So, who does Intel have in mind with the new CPUs? Internal assessments puts 3-5 years as the target upgrade window, i.e. those still utilising Ivy Bridge and Sandy Bridge CPUs. Their own benchmarks, utilising tools which tax CPUs to the limit place them rather than place them in the context of their likely workload, pegs them as approximately 30% faster than equivalent Ivy Bridge products (although not, it must be stressed, on a clock-for-clock basis). However Intel still face an uphill battle amongst users caught in the question of whether their Sandy Bridge 2500K or 2700K remains sufficient.
With that introduction out the way, it’s time to move on to the features of the new CPU generation.