I see your point...now i have unearthed something
Here u can find that the height of both Corsair XMS3 and GSkill Ripjaws is ~41mm.
Also from here the height of Ripjaws X is ~40mm
From here the height of Corsair Vengeance modules comes to ~50mm
I have also decided to go for the CM Hyper N620 as it will be sufficient for my needs...no need to get the U12PSE2 shipped and all...
However the clearance (from here) of the N620 appears to be ~40mm...
Will it cause any problems????...
In my case, the N620, with the fans facing towards RAM and rear fan respectively, I can actually use any RAM regardless of their height because the cooler completely stays clear of the RAM slots. Love it!!!