Stability issues with Z97E-ITX/ac mainbaord

Due to the lack of other options I have been running the board with turbo and speed step disabled for a while now and I can say that it has been stable with that configuration. I haven't experienced a single crash. Loading the UEFI default makes it unstable again.
I have been searching the net for this problem and have come to the conclusion that I am far from alone with this issue. Lots of other people have had issues with Broadwell CPUs on desktop boards (not only on ASRock boards), but other manufacturers have released BIOS updates since, that seem to fix those issues (e.g. Gigabyte and ASUS). Since I can't find an update on the ASRock website, I was wondering, when I can expect an update?

The way this is (or isn't)  resolved will surely have an influence on which mainboard brand I choose next time. I liked ASRock boards due to their usually good power efficiency, but not being able to use a CPU properly that is supposed to be working on that board, does not leave particularly a good impression.

Yes, the CPU speed is locked at the default clock with those two options disabled. Transitioning between the CPU's C states on the other hand works just fine (it remains mostly in C6 when the CPU is idle). Since those transitions between C0 and the higher C states cause a large difference in current flowing it does not seem to me that the power regulators can't keep up with the changes, otherwise I would expect the system to crash even with turbo disabled (even if maybe less frequently).

I don't know exactly what those UEFI updates contain, as the changelogs are usually rather vague, somthing along the lines of "Improved stability for Broadwell CPUs" or "Better system compatibility for 5th generation processors".

My question is still unanswered. Will there be a BIOS/UEFI update any time soon? It can't be that difficult to replace the microcode in the BIOS with the new version.

Ouch... thank you for this not unimportant thread. An i5-5675C is practically ordered here, but now I have to delay this, too bad. I also hope that an updated UEFI/BIOS for Z97E-ITX/ac which fix this issue will be released soon.

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