B85M Pro3 Multicore Enhancement

For your i5-4590 processor, 3.5GHz is the standard all cores maximum Turbo speed.

It seems you changed to UEFI/BIOS version 1.40 at one time, but went back to 1.30, is that right?

Before you changed to 1.40, when using 1.30,  Multicore Enhancement set all the cores to 3.7GHz, is that right?

If all of the above is correct, I believe Multicore Enhancement is not working because of the Update microcode 19 change in 1.40.

Multicore Enhancement and the non-Z OC features most mother board manufactures provided at one time for non-overclocking chipset boards like your B85, did not make Intel happy.

Intel is very strict about which boards can have any type of over clocking ability. Only the 'Z' model chipsets, since Intel's 7 chipset series, are allowed to have any over clocking features.

It took a while, but Intel forced mother board manufactures to take back the over clocking features on non-Z chipset boards. That was done by a special CPU microcode update, microcode 19, sorry to say. Intel also had Microsoft release a Windows Update that did the same thing, IIRC.

CPU microcode is part of the BIOS. CPU microcode is not updated or over-written by every BIOS update. So if (when) you applied 1.40 to your board, you changed its microcode to the one that blocks the Multicore Enhancement option.

Changing to BIOS 1.30, which does not change the microcode, will not give Multicore Enhancement back. Sorry to say, it is gone forever now, given all of the above is correct.