So basically Noctua has the best fans in market ? What about Thermalright looks very similar to Noctua.
NF-P12 and NF-F12 fans I've had come with (expensive) Noctua heatsinks have been rather lousy for the premium.
While maybe fooling dB-meter P12's acoustic signature has quirks.
And in case of F12 is never any calm/smooth...
Likely because of those truts nearly parallel to trailing edge of fan blades causing bigger "bumps" to airflow separating from blade.
I mean just blow air from your mouth and then move finger or pen sideways back and forth through that airflow...
You'll get lot more noise.
Even worser is vibration.
They were like some darn vibrating rollers when held in hand and when on table it would amplify noise.
Should be easy to deduct what such vibration does, when you attach fan to case!
At the same time original sleeve bearing Scythe Slipstreams costing third of those hype Noctuas are free of vibration and have very smooth sound profile, with noise coming only from airflow.
(and they move more air per RPM than most fans in low/ish impedance use because of blades covering bigger percentage of fan diameter)
Also ball bearing Scythe Gentle Typhoons have very smooth rotation and no real bearing sounds.
Really shame paths of Scythe and Nidec-Servo separated.
Well, Scythe Kaze Flex looks really good geometry wise with Slipstream like design and should have good life span, unlike Slipstream.
I do like side panel windows but only because they are great for visual inspections to look for dust build-up and to make sure all fans are spinning. Other than that, I tend to pay attention to what's on my monitors.
Everyone can argue all day long about which "type" bearing is the best. But the point is moot unless the quality of manufacturing and assembly of those bearings AND the quality of design and the characteristics of the fan blades are factored in too. A silent fan motor coupled with bad design fan blade may still be noisy, and may move little air.
That's indeed only really useful function for side window.
Though I guess some like staring more parts of their computer than actually using it.
Btw, once when assembling new PC with Seagate Barracuda ATA IV drive actually opened the case to check that I had truly connected it, because at the time pretty much all other drives made lots of noise.
Even good bearing and design isn't enough if materials are bad and easily resonating.
The fancy "metallic" plastic used for the frame may look flashy, but it's terrible for sound. Lightweight and brittle, the material picks up fan vibration easily and audibly, giving the fan a highly resonant character. At slower speeds, the resonance manifests itself as a deep buzz or growl, while at higher speeds it's more like a pure tone.
http://www.silentpcreview.com/article739-page3.html#silenx
The acoustic difference between the opaque Globe fan and the transparent AcoustiFan was quite remarkable. We've often said that transparent plastic is unsuitable for use in quiet computers, and listening to the two fans side-by-side demonstrated why. Both fans demonstrated the same underlying growl that increased in pitch and volume as the speed increased, but the transparent AcoustiFan also had a ringing overtone: The sound of the brittle transparent plastic resonating.
http://www.silentpcreview.com/article739-page5.html#acoustifan
Though I've met few translucent Nanoxias which seemed to avoid resonance problems.