Just thought I'd drop a note about this fan as purchased to replace the stock fan on my CoolerMaster Hyper 212 Evo cpu heatsink. That stock fan - as detailed at viewtopic.php?f=14&t=65208
- I found too loud and had an annoying warbling resonance at the c.1000rpm that my motherboard insisted was it's minimum speed (Speedfan tinkering was fine but never quite solved the warbling).
There's not a whole lot of choice in quiet PWM fans in the UK. Sycthe Slipstream would have been my first choice but availability of those in the UK is poor, the new Sycthe Glidestream another option but availability of the PWM models in that range also poor (QuietPC.co.uk have most of the range though). Noctua and Noiseblocker are available but I begrudge paying £17 for a fan. The beQuiet model was about £12 on Amazon.
Ok, some figures, and some subjective noise experience. I figure RPM at a given PWM duty cycle is going to be of most use:
The subjective experience is when closed up in a Fractal Define Mini as described at viewtopic.php?f=14&t=65208
- the only difference being the case is now only running ONE case fan at c.540rpm (potentiometer on fan controller popped, going to revert to Y-fan splitters and BIOS control only)
10% = 350rpm inaudible
20% = 350rpm inaudible
30% = 360rpm inaudible
40% = 550rpm inaudible
50% = 820rpm with utmost concentration can just about pick out the noise from the background
60% = 1040rpm very barely perceptible
70% = 1250rpm faint air whoosh, constant pitch, volume likely considered acceptable by most SCPR and "silent" by non-SCPR minded individuals
80% = 1480rpm air whoosh, very slight (really have to tune into it) pitch variation cycling at about 0.5hz. Volume roughly equiv to stock coolermaster fan at around 1000rpm, too noisy for SCPR types but still likely considered "quiet" by, erm, normal folk
90% = 1570rpm air whoosh not much louder but pitch variation is now distinct, like a second higher pitch cycling frequency overlaid on top of the whoosh
100% = 1570rpm as above
I can't really comment on the air flow as don't have tools to give a meaningful measurement, all I can say is that with my 73 watt i3-530 idling, the CPU fan running at 560rpm and the single case fan running at 540rpm the CPU temp is currently 31C. This compares to the 24C I recorded with the stock coolermaster fan running at 990rpm and three case fans all running at c.500rpm.
A quick note about the frame - as can be seen from photos, it's not got a full frame but rather a central spine with rubber standoffs either side at each of the four corners. Standard fan screws can bore into these standoffs or the supplied plastic push bolts can be used when fixing to a case. I suspect this is as good an isolation system as the noiseblocker multiframe approach but it may hinder usage on some CPU heatsinks, particularly those using wire clips, that are expecting a standard frame shape. For the record, it works just fine on a coolermaster hyper 212 though.
Overall, very wide range of speeds with pleasantly low starting RPM, ramps up quite conservatively. Constant character until the top end of it's RPM range. About two thirds the price of Noctua/Noiseblocker and reasonable availability in the land of tea and scones.