IMHO the reason that early v4 ES not running on gigabyte is not that's not wanted,How big of a deal are future mobo compatibility issues with early steppings? It seems Asus and Gigabyte X99 mobos dont support early stepping chips at all but Asrock dont seem to care: Intel Xeon E5-2683 v4 Broadwell-EP CPU 1.6GHz 16-Core 120W Max 3.0GHz QH27 ES
Will Asrock start to care and lock out early stepping chips? Has that ever happened before?
they're biosprogrammer is not as sophisticated as the asrock's are.
The early 4 ES runs not on ASUS x99, but fine on ASUS Z10xxxx.
The early v3 ES running fine on gigabyte x99, what i saw is my ga-x99M gam5 has an very old microcode rev. for v4 ES than asrock has...maybe a reason.
ASRock i.e. starts mobo's to overlock Skylake CPU by BCLK, and later Intel inhibits that with new microcode.
So i dont think ASRock will stop early ES support.
There are v4 QS but very expensive and hard to find, more will come later on the market, its still to early for those.
If you worry about, buy haswell-ep v3 QS.