According to a Chinese source, Intel may be bringing back BCLK overclocking for non-K series processors. The suggestion is that Z170 motherboards will allow the BCLK setting to be changed on non-K Skylake CPUs, allowing them to be overclocked. Another interesting tidbit is that Skylake may allow BCLK straps to be applied, meaning the BCLK can run independently of the PCIE, allowing for much great BCLK overclocking. As you can see in the image below, an i5 6400T is taken up to 2.8 Ghz (Stock 2.2 Ghz) via a BCLK boost to 133Mhz.
Older overclockers may remember the glory days of simply turning up the FSB to overclock budget chips to match much more expensive ones. There was no need for unlocked multipliers to let my lowly E5200 or E3300 gain a 1Ghz or so. That all changed eventually with the adoption of the QPI/DMI and when the PCIE bus became linked to the BCLK. If one pushed the BCLK too high, the system would become unstable as the PCIE bus could not be taken more than a little over 105Mhz over the base 100Mhz.
For both Sandy Bridge and Ivy Bridge, users were able to use Z68/Z77 motherboards to overclock their non-K CPUs a bit by turning up the turbo boost up 4 bins (400Mhz). Some motherboards were also able to overclock K series chips despite not being a Z series though Intel quickly clamped down on that. This change though might be here to stay as delinking the BCLK from the PCIE bus is more of an architectural change.
Given how BCLK straps have worked in the past, there likely only is an option for 133 and maybe a 166 Mhz. This in practice will mean an OC of 33-66%, with lower OCs being possible by lowering the multiplier while increasing the BCLK. Given how temperamental BCLK OC can be, it’ll be hard to judge how well this will work in the real world. Given that we only have a little more than a week left, Skylake may once again allow cheaper overclocking, with a Z170 board of course.
Thank you BenchLife for providing us with this information
