Before I get into the specific number comparison, it's time for some idle observations of the fans themselves. Outwardly on their exteriors they really don't look all that different than "standard" noisy fans, but (and it could just be me and my somewhat questionable behavior as a youth catching up to me again) but the fans seem heavier and have thicker blades than other fans the same size. The 60mm fan in particular appears to have a "pitch" on the blades that is steeper than other 60mm fans I looked at. This higher pitch may in fact be how the fans are moving similar amounts of air at lower RPMs than similarly sized fans, but don't quote me on that one. I may be stretching things to find a difference, who knows.