Asrock X99 OC Formula overclocking problem

That does not sound good. Your testing on three of the same boards seems to verify a problem with UEFI 2.00.

Besides a bug, all I can think of is a change in one of the CPU options. It seems as if Turbo is disabled, which would keep the 5820K at its base clock, 3300MHz, as you said you see with your CPU. Perhaps the Turbo option is really Disabled when it is set to Enabled. That would be a simple, but major bug.

I've read that other CPU settings can cause Turbo to not work. That was either SpeedStep or C1E.

Did you check the Advanced -> CPU Configuration screen in the UEFI? Perhaps an option was added or changed in that screen that is causing this to happen.

What are you using to check the CPU speed? CPU-Z? Did you try more than one program to check the CPU speed?

Your English is fine, I understand what you wrote.

I don't have your X99 board, so I can't test this myself.

I don't know what you could be doing wrong when you overclock using the 2.00 UEFI/BIOS version. If you do the same things when using 1.80 or 1.90, but that fails when using 2.00, I would tend to agree 2.00 might have bugs.

You could try using one of the automatic OC setting options in the UEFI/BIOS with 2.00, but you are probably sick of changing to different UEFI/BIOS versions.

As you said, I would want to see reports from other users of the X99 OC Formula board if 2.00 can overclock fine or not.

Thanks for the information but we must be very sure something is wrong with 2.00 before we decide it is has bugs.