Asrock Mainboard’s BIOS Feature Unlocks CPU Multipliers on Intel H87 Platform

Backdoor in Intel H87 Core-Logic Greatly Simplifies Overclocking of Unlocked Microprocessors

by Anton Shilov
06/26/2013 | 11:08 PM

Even though the latest Intel Core i7 “Haswell” platform supports respectable amount of overclocking capabilities, they are only officially available on Intel Z87 chipset and select K-family microprocessors. However, it appears that there is a backdoor in Intel mainstream core-logic set that allows to easily overclock all Intel Corp.’s K-series microprocessors on a platform not supporting unlocked CPU multipliers.


Asrock Fatal1ty H87 Performance mainboard based on mainstream Intel H87 chipset and designed for enthusiast-class systems not intended for overclockers comes with an interesting BIOS feature called “non-Z OC”. Once enabled, the feature allows to overclock any Intel Core i-series “Haswell” microprocessor with unlocked multiplier using processor’s ratio multipliers (which are only unlocked on expensive mainboards based on Intel Z87) on the platform, reports Tom’s Hardware web-site.

At present, it is unclear whether this is an exclusive feature of Asrock Fatal1ty H87 Performance mainboard, or a bug inside Intel H87 chipset. The capability clearly needs an investigation, but at present a combination of a particular mainboard and an Intel Core i7-4770K processor allows to get premium performance using a less advanced and costly mainboard. Unfortunately, Asrock’s “non-Z OC” feature does not unlock multipliers on non-K microprocessors.

While the BIOS capability lets enjoy unlocked CPU multipliers on mainboards that are not supposed to support such feature, it should be noted that Intel H87 chipset does not support a number of other enthusiast-oriented capabilities (e.g., proper multi-GPU support) that are available on Intel Z87 platforms.

Intel did not comment on the news-story.