Z170 Extreme4 overclock non-K CPU works?

NotLikeThis wrote: Hello, Im thinking to buy i5 6400, and this z170 extreme4 MB. So i want 100% be sure that i can overclock it with this mb with any bios in it (i not sure what version will be there in shop). So 3.40 version of this bios supports Blck overclock for non-K? (i heard that you still can do it, by click X on load screen, but may be guy confused ) If not, and MB will be with high version of bios (2.90+, or last 3.40), can i 100% downgrade it to 2.80? (saw problems on asus z170p with last bioses, and don't wanna same) Thanks

The quick answer to the question in your thread's title is No.

BCLK over clocking of non-K processors is gone, it is history, Intel killed this feature, and it won't be back. It is not available on any ASRock Z170 board, sorry to say.

Instead of going by what a random person in a forum tells you (and no, I am not a random person),  without knowing the details, do you see any mention of non-K over clocking on the Z170 Extreme4's information page? No, it is gone. It was there at one time, along with the other ASRock Z170 boards, but not anymore.

BCLK over clocking, or Sky OC as it was called, was a feature added, for this board, after UEFI version 2.40. No idea the exact version, but it was removed, as can be seen in the gap between versions on the UEFI/BIOS download page:

http://www.asrock.com/mb/Intel/Z170%20Extreme4/?cat=Download&os=BIOS

You can see that version 2.90 killed off Sky OC. Version 2.80 might have it, I don't know. But apply any UEFI version beyond 2.80, and Sky OC will be gone forever on your board. Even if you apply the Sky OC UEFI version again, it won't fix it. Plus, Intel had Microsoft create Windows updates that kill off Sky OC if you don't update to a non-Sky OC UEFI version.

If you buy one of these boards now, chances are it will NOT have a Sky OC UEFI version out of the box, unless you get super lucky. Sky OC has been dead since February, 2016, so you missed it by over six months. Never heard of a "click X on load screen" to enable Sky OC, that feature was either available or not.

Finally, Sky OC was not perfect. It had drawbacks that did not exist in the past when true BCLK over clocking was discovered by users, not a feature provided by Intel or a mother board.

You can't use the Intel integrated graphics with a BCLK OC. The board's VCore reading will no longer be accurate, you won't really know what it is. That can be dangerous.