PERFORMANCE TESTING

Testing methodology

Testing was done with the fan mounted on a single Swiftech MCR120QP radiator, with the fan controlled using a dedicated fan controller (Aquacomputer Aquaero 6 XT) in PWM mode. The controller also enabled RPM readout. Linear airflow was measured using an Extech 45158 Thermo-Anemometer 6″ away from the fan such that it measured the airflow in feet per minute through the radiator. Fan noise was measured in an anechoic chamber of size 5′ x 8′ with ambient noise level ~19 dBA and a sound probe held 6″ away to measure the sound volume in dBA accordingly.

Results

We see that the fan has a PWM duty cycle of 45-100%, and the RPM response curve is excellent here- very linear with next to no deviations anywhere. The fan RPM went from 1367 at 100% to 417 RPM at 45%, and this by itself is a very good range of control. But keep in mind that the rated fan speed is 1450 RPM here. I do allow a +/- 10% deviation so this fan falls in within the range now, and this is a reason why I was surprised about Corsair not listing a deviation range themselves. This is not a big deal by itself though.

What IS a big deal, however, is the PWM implementation in these fans that make them hard to control with a fan controller such as the Aquaero 6 that strictly follows the specifications from Intel. Remember the part where I said I had 8 of these before? I had done a test of noting down the fan RPM from the Aquaero by adding in 1 fan each time to the same header using a standard powered PWM splitter (verified to be working by testing with other PWM fans) from 1-8. This is what I got at 50% PWM signal (where the single fan speed as seen above is 464 RPM):

As you can see, as you keep adding fans to the same header the fan controller can’t keep up with providing the same amount of PWM control by the rapid switching on and off of current and by the time you are on fan 5, you might as well be running these full speed itself. Now you could argue that Corsair had followed the fan industry specs here (this is a result of the Aquaero not having a pull-up resistor in the PWM line as I know it) by having the SP120 PWM fans consume no more than a 1mAH power from the PWM line but then again the Aquaero, as with most other PWM controllers and splitters, follow the Intel specs in not having the pull-up resistor to aid in this. Standard fan industry practice is also to drive 1 fan per PWM channel/header so really this is a case of two standards not being compatible with each other. Does this mean Corsair is at fault here if everyone else who makes PWM fans or pumps has accommodated for this? Perhaps, perhaps not- motherboards should be following the Intel specs fully but some seem to have a pull-up resistor to allow for such things introducing yet more variability here. My point here is this: if you are planning to use these fans with a PWM splitter/controller then do some research before pressing the buy button.

Back to the sole fan now! Let’s now see how it stacks up against other fans that are rated to have a max speed in the 1201-1500 RPM range:

Please do click on the images above to get to a full size version if that better helps view the results. If you have any suggestions on plotting software that can do a better job, I would welcome suggestions also. We see here that the SP120 PWM QE is not really very quiet compared to the other fans tested out so far, but the fan noise comes from the part where it blows more air through the radiator than most others in there. Unfortunately, the increase in noise is higher than the increase in airflow and so when we see the last graph on a performance/noise basis, the SP120 QE is average at best here. Keep in mind that there are some VERY good radiator optimized fans in here and keep checking in to see if more fans have made it in here.