By chance, would you know the maximum CFM of these fans? Are they 3-pin (it looks like it in the picture, but difficult to tell)?
No way of knowing the exact CFM on these, as SilverStone never provided that specification neither online nor in the paper manual. Of course, CFM and static pressure are going to be variable by RPM speed, and based on experience I can estimate that these are within the 90 - 100CFM range (don't quote me on that). All in all, this particular design was chosen by SilverStone for its first 90-degree ATX chassis (which I have reviewed), and the airflow is plenty and very abundant.
But to answer your other question, yes they are 3-pin.