Corsair Link with Air Series Fans distinct clicking noise AF120/140

Today I just got corsair link to further complete my build and I thought manage my fans and quieten down my pc.

I hooked everything up with all of my fans, apart from the quiet SP's I have every Corsair Air Series fan!

The thing I have noticed is when I turn the AF fans below 100% they start clicking irrespective of RPM. This includes AF140's and AF120's but on the SP120's it is far less noticeable. I am not mad or hard of hearing I have checked this on every single fan I have and all 6 do just the same thing. On anything but max RPM whether it be 750 or 2100rpm.

HOWEVER this did not occur on the previous firmware of the cooling node but that only allowed a minuscule variation in fan speed. It also does not occur when using the fan controller on my H100 but again that only gives limited variance in speed. So from my own process of elimination I can tell you Corsair that the current firmware v1.2.5 is somewhat incompatible with your own fans.

From recent information, it maybe that Corsair Link Cooling is modulating the power supply (the 12v to the fans). A prominent noise characteristic from PWM speed control of the 12v power stems from the fan's torque characteristic. Stator excitation is a square wave which is switched "on" (usually) 45 degrees before peak torque position and switched "off" 45 degrees after peak torque position. This excitation causes a small amount of ripple in motor torque at the frequency of commutation. Each small torque burst causes a minute flexing of the entire fan structure and results in a faint (but audible) "ticking" noise whilst the fan is operating.

This is true mostly in larger fans (i.e., fans with operating currents in excess of 300mA), since they generate a greater amount of torque and have larger size and mass. This effect is also more pronounced at lower operating speeds (i.e., low PWM duty cycle) because the "ticks" are farther apart and easier to distinguish.

Hope you followed this fairly heavy explana:bigeyes:tion

I follow your explanation entirely Macforth.

Do you think it does damage to the fan motors or are they built to handle that? Is it a characteristic of all PWM fans or are the Corsair ones especially bad.

The earlier firmware didn't cause it at all but the fans only slowed down about 100-200rpm so it more or less made no difference.

I may switch out some of my fans for the 140mm's where possible and have them run at fixed RPM then leave the ones in the case I can't hear to tick in peace. Its just that I have two fans in the side panel right by my ear so they are either maxed out making air whine or slowed down ticking right in my ear. :D:

Sorry for my tardy reply. In answer to your questions: no, I don't believe that any damage will be done to the fan. The clicking is a characteristic of 12 volt modulated PWM control. The Corsair are not "especially" bad, their design is similar to most three wired fans. By "ones" you may also be including the Corsair fans as being a PWM type. If so, that is not the case.

I understand if that is a bit baffling, so I will summarize the ways in which fans are controlled. The first is by resistance. This works for all 3 pin fans and PWM fans. It is simply a resistance is placed in the 12 volt line. If that resistor is a variable type, then the fan speed can be varied. The advantages of this method is that it is simple, but the disadvantages are that the total power in remains a constant, even if the power to the fan has been reduced by the resistor. the difference between the two is expended as heat, and we see big heat sinks on FETs and Regulators. Further, one can not slow down a fan sufficiently with this method.

This may not seem big deal for a couple of normal use case fans, but when using a greater number, such as a push pull of three rads, or worse.....server fans....then the heat generated and the wasted cost adds up. Some server fans such as Delta, Sanyo Denki, NMB-MAT, Papst, Sunon, and Nidec, can draw in excess of 4A!

So PWM was born....firstly in the server world. But to make the waters even more murky....there are two (2) types of PWM.

The lesser used one is the modualtion of the 12 volt line. To help to understand this, imagine the 12 volt line being turned on and off extremely fast. There still exists some problems by using this method...some power loss......the loss of the tacho line, a lack of smoothness, and sometimes a "clicking" sound. The tacho loss is due to the constant 12 volt feed being stopped and started.......and thus the tiny tacho coil in the fan fails to be able to send information back. There have been a couple of methods used to try and over come this, one by stopping the modulation every now and then.....then averging the results between bursts. When applying this to server fans that can range from 800 rpm to 6000, this method failed. Another method is by trying to time the exact moment the fan magnet point passes the coil, but this is a tad messy, and results in waving results or other inaccuracies.

So a more efficient method was born.......and that is the 4 pin PWM controller. PWM fans and small motors such as water cooling motors have some miniture electronics aboard, that allow for this later method. In four (4) wired PWM the pinout is: 12 volt.....earth......tacho....PWM. Early development of this type used modulation on the 4th line switching (modulating) a voltage signal very fast. Some early frequencies were as low as 1 KHz and 16 KHz came later. Many of the 120mm x 35mm server fans still have a 16KHz frequency on a 5 volt 4th PWM line. They were very popular for the aircooled overclockers......spinning up to huge revs......pushing huge quantities of air......but at the same time sounding like jets taking off.

Later, Intel put out a paper to all motherboard manufacturers notifying them that they were about to support 4 pin PWM for their CPU's, and since that time we have seen motherboards offering this at their CPU outlet. This 4 pin PWM has a frequency of 25KHz on the 5 volt line. Since that time, this type of PWM ..using 4 wires, has become the norm in the enthusiast PC community. All PWM fans and PWM pumps such as the MCP35X2, conform to this norm.

The advantages include the ability to slow a fan to a very low speeds......but that fan still remains smooth and there is no waste power or generation of heat. For the water cooling enthusiast, it means that they can bring a 12v line and earth straight from the PSU and just use the motherboard's tacho and PWM outlets. When using a dozen or so fans, they cannot be just all joined and plugged into the MB as the total power drawn is above that which the motherboard can handle.

In the computer world, especially amongst the set of people that frequent this type of forum, 3 pin fans are still in greater numbers than 4 pin, PWM fans,.... however more and more manufacturers are now offering PWM varieties, and ownership of 4 pin, PWM fans is on the rise. Are they better than three pin fans? No, the figures that we are mostly interested in.....CFM, pressure and noise are no better (or worse) in 4 pin PWM fans, but what they can boast is the abilty to control in a smooth and precise way down to very low speeds.

Having raved on for too long, I will summarize with respect of your particular comments in your opening thread. You are using 3 pin fans..not 4 pin PWM fans. The "ticking" you are hearing matches the experience of others who used a 12v line modulated type controller. I do not own the controller you are using so I am not positive it is this sort of control, but believe it to be from comments made in this forum. I would need to check one with an oscilloscope to be certain. Lastly..your fans will not deteriorate on the evidence available at this time.

Thanks for taking the time to explain in great detail!

Now I have my pc completely together it sounds much better, still fiddling as you do... :D:

Ahh thankyou for the kind words.....but as I am an ORF...I guess I can afford the time. Oh, an ORF has the word retired in there somewhere.

One thing though........the frequency does not change. The definition of frequency is the number of cycles per second. The change to speed of the fan is controlled by changing the behaviour within each cycle. At it's simplest, each cycle has a % of "on" and a % of "off". If each is half then that is described as 50% duty cycle. If the % of "on" is 75%, then we say the duty cycle is 75%.

When the duty cycle is 50% on and 50% off, it's as though the fan sees 6volts and slows accordingly. When the duty cycle is 75% (75% on/ 25% off), the fan behaves as though 9 volts is being fed to it.

If we have a duty cycle of 75% (such that the fan is behaving as though 9 volts is being fed to it), and there are 1000 of these duty cycles, we would say our frequency is 1000Hz or 1KHz. If we could change the frequency to 10KHz, the duty cycle has not been changed, and the fan would still behave as though 9 volts is being fed to it.

Hope this assists in understanding that it's not the frequency that is changed to control the speed of a fan, but rather the % duty within each cycle.

Ok guys steady on with the explanations before it gets so complicated I no longer understand! So with later firmwares is it planned to increase or adjust the frequency of the PWM to reduce the noise?

What control does the H100 use in comparison as that never makes any fan noise but only gives a tiny amount of control (with my fans anyway). If the cooling node gets refined with the coming firmware's then I may be tempted to get another to replace the H100's fan controller just for the extra control.

I know this thread is quite old, but my Corsair SP120L that came with my H80i started to make a clicking sound when the RMP start ramping up under load.

[ame]https://www.youtube.com/watch?v=QFbGpveqsOQ[/ame]

Is there an at home DIY fix for this? I don't want to send in my H80i for RMA just for a set of fan because I'm sure shipping will cost half of what I paid for the H80i

Have you tried a different fan header on the H80i or switched connectors on the y-cable or plug it into the motherboard? Does it still click?

If so, Request an RMA to replace the fan. From what i have seem here you do not need to send the H80i or the fan back. Just make sure you upload a picture of the invoice as proof of purchase.