Well.. I see what you mean. But I think, that air may not be able to escape, since it is beeing blown in direction of other fan (at least part of it). It may be, that considerable amount of air that is used to cool procesor in fact just came out from the other fan and is quite hot (you know - those fans are quite powerfull and are not all that far from each other). Anyway - how to explain that difference in fan speed??
By the way - after reboot Intel's fan is rotating much slower (and so does AMD's). But Intel's temperature is 10* higher, while AMD's is no different than it was.