Well I am gobsmacked by this! Like everyone else, I have had the "clock interrupt" BSOD on my Z68 Extreme 4 since the day I installed it. There is a huge body of evidence on this forum that suggests a fault exists on this board whereby there is insufficient power provided to the system at idle when using the onboard graphics. Upping the Vcore or adding a graphics card may solve the issue (both worked for me), but these options cannot be advocated as the solution. The board must work as advertised using default settings and onboard graphics.

It is insulting to suggest that the problem can't be duplicated in the Asrock labs. I notice you use the wording "we hardly see the symptom on our side", which suggests that you are able to duplicate the problem.

It is insulting to suggest we try a beta bios (which is older than the published bios), when all that seems to do is set a fixed voltage. This will clearly interfere with other aspects of the board settings, especially power saving functions, and will also increase wear and tear.

It is insulting to suggest that our memory is faulty. I use Corsair memory specifically recommended by ASRock, and many others use various, high quality memory chips. If high quality memory chips are incompatible with this board, then the problem lies with the board, not the memory.

It is insulting to suggest adding a video card to fix the problem. I specifically bought this board for the onboard graphics. It was cheaper than competing boards from Asus or Gigabyte, but if I have to buy an extra video card, then it becomes more expensive than buying an A-list brand. Also, people who use onboard graphics have power saving and low noise as their priorities. These features are defeated by adding a video card.

If Asrock is unable to fully fix this fault by firmware, then it must do a product recall because as it stands, this product is unfit for purpose. This is the first Asrock product I have bought, and will be my last. I will also advise my clients to avoid this brand.