my Noctua NH-D14 doesn't give me enough clearance on my first 2 DIMMs so i'm stuck running my ram in dual channel. I can't keep 4.2 Stable on my i7 950 and im thinking thats probably the main reason but I can't be for sure on that. I have Dominator GT 1866 9-9-9-24 DIMMs but I think the heatsinks can come off, I just don't have the proper tool to do it.