Hmm, Id keep speedstep enabled, i tried disabling it on mine to have clocks always at 4.0ghz but it just stopped it going above its 3.3 base instead. You could try it though, maybe xeons act differently lol. Xeons on X99 seem to be a completely different beast.

Currently setting up a work PC, 3770K 16gb ram and a geforce 210 (to free up ram and since the iGPU on it this doesnt seem to work well since i delidded it), and i just put it all together and it just works, set xmp on the ram for CL8 @ 1600MHz 1.35v (some nice DDR3L heh), -0.1v on the cpu vcore offset. No problems at all, just boots up, really snappy. Ready to go. No instabilities at all

My current X99 system? Heck no, so much fiddling, disabling and enabling things to get certain things to detect. Insanely slow boot times (15-17s before the screen even comes on) and then overclocking to a measly 4ghz was more annoying. No matter what voltage i pumped through that tw*t it would just hang at idle, manual voltage or what. Finally figured it was cos of c states. But my Z97 system had all c states enabled at 4.8 and was happy as larry... thought X99 was supposed to be advancement and progressing, not kind of a fiddly sidegrade with more cores and more pcie lanes. The ddr4 controller aint even that great. Pulling 60GB/s on 2400MHz quad channel, where 2133 should hit around 65. Overall im just not really impressed by X99. Its fast sure, but all the effort just to get basics working that should work anyway... ;-;