Recently we've seen a lot of BIOS releases that enable the overclocking of Haswell K-series processors on B85 and H87 based motherboards, but now Intel is cracking down on this, forcing consumers to purchase the more expensive Z-series motherboards. TPU writes Intel is developing a new Haswell CPU microcode update that will disable the overclocking on chipsets other than the Z87:
A microcode update can be deployed both through BIOS updates, and surreptitiously through Windows Update. Intel's used the tried and tested "stability" bogey to justify the update. While it's true that motherboards based on B85 and H87 tend to feature weaker CPU VRM, there's nothing to say that ASUS wouldn't have gone on to design its next ROG Maximus on H87 Express, and save on manufacturing costs. While it's purely hypothetical, something like that wouldn't be in Intel's commercial interests. What next? Intel will push this new microcode update on to motherboard vendors, instructing them to issue BIOS updates with it; and future batches of Intel "K" CPUs may not support overclocking. If that isn't enough to contain the problem, Intel may give Microsoft a ring, and ask it to push the update through Windows Update. It tried that once in the past.