Well i know on dell's top desktop comp 8200 uses a Datech or also known as JMC or RDJD, as 92x32mm fan that passively cools the CPU and really the only case fan, seems shitty but surprisely does the job well.
Specs on the Datech fan in the 8200, its varible by temp, but usually sits at 15db! 20cfm...i don't know its specs at higher temps, but i've never seen it even speed up, so i guess lets not worry about it
When I worked at my local comp shop I never saw NMB in any pre-built comps (ya know like compaq, dell, gateway, micron, intel and so on)...its mostly Nidec espically in servers Nidec is common, Sunon on occasion, Delta i saw or rebadge of Delta and Sanyo Denki.
GiZzO's Fan Database Page