IDK much about the Maximus. I have however used RC TweakIt for OCing. Perhaps you need your core multi set to:
By all cores (can adjust in OS)
And leaving things set on auto may override any increase attempts, IDK.
Also, if you have installed Ai Suite it can be setting things, fighting W/RC TweakIt. Turn off all adjusting functions in Ai Suite including auto tune.
i7-3930K; Asus RIVE; G.SKILL Ripjaws Z 4x4GB DDR3 1866; MSI 7870 2GD5/OC; Crucial M4 SSD 256GB;
Corsair 1000HX; Corsair H100, 4x Excalibur 120mm PWM CPU Fan p-p, AS5; SB X-Fi Titanium Fata1ity Pro;
Dell U2412m IPS 1920x1200; Cooler Master HAF 932 case; Tripp-Lite OMNIVS1500 UPS fully Line-interactive.
(EVGA site: )
And I have a second (wife's) computer,
Eve.Overclocking is useless to me if it is not rock stable.