Haswell Non-Z Overclocking Solutions
Before Sandy Bridge CPUs, there were two main routes of Intel CPU overclocking – changing bus clocks on motherboard for all CPUs, and the unlocked multiplier for the very expensive high end models. Sandy Bridge and later CPUs severely restricted the range that FSB could be overclocked to, leaving only K versions of CPUs with unlocked multiplier as an option for a big overclock. While those K versions of CPUs are only around $30 more expensive than base versions (unlike earlier very expensive Extreme Edition parts), the overclocking ability on Sandy Bridge and later still requires a premium chipset and more expensive motherboard. This limitation however is not a technical one, it is just Intel marketing, as several recent updates from ASUS and others have shown.
Intel offers the top-end Z87 chipset as the only option with overclocking support. ASRock was first to release BIOS updates, allowing changing K versions' Haswell CPU multipliers on cheaper B85 and H87 chipset based motherboards. Later, ASUS, Gigabyte, Biostar and ECS have followed suit. While the overclocking feature is getting unlocked, the boards that were not designed with it in mind may offer lower maximum overclock than Z87 solutions. While motherboard manufacturers may try to release cheaper motherboards with better power management for OC, there is no guarantee that Intel will not restrict this feature in newer manufacturing runs. While it lasts however, there is an opportunity to build a cheaper powerful PC for those who do not need other features of Z87 chipset.