UPDATE: Although we suspected that this was the result of an Intel/Asus collaboration, it looks like that is not the case. After reaching out to Asus, we discovered that Intel has nothing to do with this. Instead of the two companies working together, Asus simply found a workaround to make overclocking possible on these platforms. Of course, we don’t know what this workaround is, but that will only make it more interesting to see how other vendors will respond in the coming few days.
Soon you'll be able to overclock your unlocked Intel Haswell or Haswell refresh CPU on a non Z-series motherboard.
Asus has announced that it is releasing new UEFI BIOSes for its H87, H97, B85, and H81 series motherboard that enable support for overclocking. While the company doesn’t guarantee that all of the processors will be overclockable in combination with these motherboards, Asus did indicate that you should be able to overclock the K series Haswell and Haswell Refresh processors, along with the new Pentium Anniversary Edition CPU.
The last CPU is probably the reason why Asus is making this functionality available. The new Pentium Anniversary Edition processor is built to celebrate 20 years of Pentium processors and comes with an unlocked multiplier. This CPU costs about $80, and it’d be a fairly pointless release if the only boards it can be overclocked on are Z-series motherboards. To solve this problem, two things can be done: either the motherboard vendor can build a budget oriented Z-series motherboard, or, as Asus is doing, release a BIOS that unlocks overclocking features. That way, you're not forced to buy an expensive Z-series motherboard to overclock your cheap Pentium Anniversary Edition CPU. Asus probably collaborated with Intel to do this, as it is in Intel's interest to have cheap motherboards available to overclock this CPU, increasing its sales.
To unlock the overclocking features users need to update the BIOS to the most recent version, and drop a CPU into the socket that supports overclocking through an unlocked multiplier. Once this is done the necessary features will automatically become visible in the UEFI BIOS. The overclocking can only be done through adjusting the multiplier, though.
Keep an eye out for a new BIOS for your board if you’re among the interest group, it should either be available already, get posted somewhere in the next few days.