What we have here today is sound and temperature tests between a Swiftech Helix (Non-PWM), Cougar Vortex PWM (CF-V12HP), and the stock Antec Kuhler 620 fan (product specs state 1450-2000 RPM). I was surprised by the results! Also had to reduce my overclock slightly to keep temperatures from shooting far past the AMD 62C core limit (normally I run two fans in push/pull, these tests were only push).
Fan RPM was controlled with an Aerocool X-Vision fan controller except for the Kuhler 620 fan. This fan has no RPM wire so it does not work with the X-Vision. The Kuhler 620 fan was controller using an old crappy Thermaltake Xcontroller. Assuming the dial goes from 0-10 the Kuhler 620 fan was tested at 0, 5, and 10.
All case fans were run 800-900 RPM to keep ambient noise low for sound tests.
Take the decibel readings from the phone with a grain of salt. The phone should have been moved further away, trust your ears. The wider the airflow of the fan, the more air was blown directly on the phone (causing higher Db reading).
Also note that the Swiftech Helix was constantly going up and down in RPM. If set to say 1000 RPM it would vary between 900 and 1100. The Helix seems to not work well with X-Vision.
Audio was recorded with a Rode NT1-A condenser mic approximately 1ft in front of the fans.
Temperature Tests. Note: the Helix was controlled via motherboard voltage control using Easy Tune 6. This resulted in much more stable RPM's for the Helix.
All tests were on the Antec Kuhler 620 radiator with an approximately 21-22 FPI (according to Legit Reviews). All rad fans were in push (no push/pull or pull). Ambient air temperature/intake temperature was recorded with a thermal sensor in Fahrenheit and converted to Celsius from the Aerocool X-Vision fan controller. All case fans were run at 12V for every test.
Tests consisted of 20 minutes of Intel Burn Test. Temperature results were recorded 19 minutes and 50 seconds into the test. The average and maximum core temperature was recorded for each test.
These results truly surprised me. I expected the Kuhler 620 fan to beat the Helix and Vortex in temps when running single fan push. I also expected the Helix to beat the Vortex.
All temperature and RPM readings were taken from HWiNFO64. Values were reset for each test run. For example here is the 1500 RPM run for Helix and Vortex:
I am satisfied w/ 2x Swiftech Helix 120 compared to CM blade master in noise... and costs the same as CM blade master
but Helix are 1800 rpm not 2000 RPM
The thing is I have two Helix fans. One hits 2100 RPM and the other ~1700 RPM. I think they used to make them 2000 RPM because the box even says 2000 RPM. The newer boxes have stickers over the specs with 1800 RPM. Here's the pic of Helix at 12V. Look at the Rad Fan RPM.