In - thats the only way Ive seen them though who knows maybe someone
will say it doesnt make all that much difference but thats the only
way Ive seen them setup,
Blowing in creates more turbulence against the 'sink fins
and subjects the fan bearing(s) to lower ambient temp. It
is almost always better. Sometimes the fin design creates
too much turbulence to air entry though, and sucking air out
of the fins is as good, for example Alpha Pal8045... but
also the motherboard and case environment can effect which
direction results in lower temps. A couple degrees temp
difference is not as important as other factors like noise
or bearing lifespan, IMO.
