During the Intel Developer Forum in Beijing, China the X86 chip giant revealed details about how overclocking will work on its upcoming Haswell processors. Enthusiasts will be pleased to know that the new chips do not appear to be any more restrictive than the existing Ivy Bridge processors as far as overclocking. Intel has even opened up the overclocking capabilities slightly by allowing additional BCLK tiers without putting aspects such as the PCI-E bus out of spec.
The new Haswell chips have an integrated voltage regulator, which allows programmable voltage to both the CPU, Memory, and GPU portions of the chip. As far as overclocking the CPU itself, Intel has opened up the Turbo Boost and is allowing enthusiasts to set an overclocked Turbo Boost clockspeed. Additionally, Intel is specifying available BCLK values of 100, 125, and 167MHz without putting other systems out of spec (they use different ratios to counterbalance the increased BCLK, which is important for keeping the PCI-E bus within ~100Mhz). The chips will also feature unlocked core ratios all the way up to 80 in 100MHz increments. That would allow enthusiasts with a cherry-picked chip and outrageous cooling to clock the chip up to 8GHz without overclocking the BCLK value (though no chip is likely to reach that clockspeed, especially for everyday usage!).
Remember that the CPU clockspeed is determined by the BCLK value times a pre-set multiplier. Unlocked processors will allow enthusiasts to adjust the multiplier up or down as they please, while non-K edition chips will likely only permit lower multipliers with higher-than-default multipliers locked out. Further, Intel will allow the adventurous to overclock the BLCK value above the pre-defined 100, 125, and 167MHz options, but the chip maker expects most chips will max out at anywhere between five-to-seven percent higher than normal. PC Perspective’s Morry Teitelman speculates that slightly higher BCLK overclocks may be possible if you have a good chip and adequate cooling, however.
Similar to current-generation Ivy Bridge (and Sandy Bridge before that) processors, Intel will pack Haswell processors with its own HD Graphics pGPU. The new HD Graphics will be unlocked and the graphics ratio will be able to scale up to a maximum of 60 in 50MHz steps for a potential maximum of 3GHz. The new processor graphics cards will also benefit from Intel’s IVR (programmable voltage) circuitry. The HD Graphics and CPU are fed voltage from the integrated voltage regulator (IVR), and is controlled by adjusting the Vccin value. The default is 1.8V, but it supports a recommended range of 1.8V to 2.3V with a maximum of 3V.
Finally, Intel is opening up the memory controller to further overclocking. Intel will allow enthusiasts to overclock the memory in either 200MHz or 266MHz increments, which allows for a maximum of either 2,000MHz or 2,666MHz respectively. The default voltage will depend on the particular RAM DIMMs you use, but can be controlled via the Vddq IVR setting.
It remains to be seen how Intel will lock down the various processor SKUs, especially the non-K edition chips, but at least now we have an idea of how a fully-unlocked Haswell processor will overclock. On a positive note, it is similar to what we have become used to with Ivy Bridge, so similar overclocking strategies for getting the most out of processors should still apply with a bit of tweaking. I’m interested to see how the integration of the voltage regulation hardware will affect overclocking though. Hopefully it will live up to the promises of increased efficiency!
Are you gearing up for a Haswell overhaul of your system, and do you plan to overclock?