"Corsair Link" permanently killed my ability to regulate CPU fan speed

[Dankk]

I have an MSI Z97-G45 GAMING motherboard, and a Corsair H80i CPU cooler slapped on top of it, with two fans in a push-pull configuration.

I had both of those fans plugged in directly to the H80i, which regulated the speed just fine. I understand there is this software called "Corsair Link" which can be used to monitor and customize the H80i, so the other day, I actually installed it for the first time ever.

After installing it for the first time, something funny happened - my CPU fans ramped up in speed, and became louder. OK, I figured this was just the new software I installed. All I wanted to do was change the color of the Corsair logo anyway; so I uninstalled Corsair Link almost as quickly as I installed it. The program seems to be off my computer, but... the fan speed didn't go back to normal?

My MSI motherboard has two separate headers specifically for CPU fans, so now I thought: Instead of having my fans plugged into the H80i, I'll just plug them directly into my motherboard, and regulate CPU fan speed from there. Nope... my CPU fans are perpetually spinning at ~1,700 RPM. I've tried to change the fan curve in the BIOS; didn't work. Turned off the fan curve completely and just turned it down all the way; didn't work. Installed MSI Command Center in Windows to see if maybe I could control it from there; no dice. What in the world is going on?

At least speed reporting seems to be accurate; all of my monitoring software says that the two fans are spinning at a constant ~1,700 RPM each, which I can believe. Ever since two days ago, I have never once heard the fans fluctuate in speed, or get any quieter. And my CPU temps are just fine; idling at 35 C or so.

What is happening? I could maybe understand if one of the fans broke, or one of the fan headers broke. But keep in mind, I'm using two fans. It would be a pretty big coincidence if both of them happened to break at the same time, wouldn't it?

Also, I have a cheap front-intake fan that I can change the speed on just fine. Regular system fans have no problems. It's purely the CPU fans having issues.

For the record, they are 3-pin (non-PWM fans). This didn't used to be an issue, but now I'm tempted to get some 4-pin fans to see if those work. However, I want try and get these working first. Any ideas?

 

[Paperdoc]

I'll answer in backwards order. First, why your fans are not being controlled by the mobo headers.

Those are 3-pin fans. By default, the two mobo CPU_FAN headers are using PWM Mode for control of their fans. Set up this way, those 3-pin fans will always run at full speed; the fan headers cannot control them using this Mode. There MAY be two ways to change that. IF your mobo actually allows you to change the control Mode for these headers, you can do it. SOME mobos allow you to choose whether the CPU_FAN headers use PWM Mode or Voltage Control Mode (aka DC Mode) to control their fans. I can NOT see that option in your mobo's manual, so it may not be possible. But IF you find a place to make that change, go to DC Mode for both of those headers and then SAVE and EXIT from BIOS Setup.

On the other hand, if your mobo does not have that option, You should concentrate on why the Corsair Link software did not appear to work. First of all, check how the H80i system was installed. It must have four connections. One is to a PSU SATA power output connector for power to the H80i system. One is a cable with a 3-pin female connector on the end that must plug into the CPU_FAN mobo header. BOTH of the fans on the radiator must connect to sockets from the pump unit. And the last is a cable that must connect from a socket on the pump body to a mobo USB2 header. THEN you install Corsair Link. It uses that USB cable to communicate with the pump unit and do all the control of the pump and radiator fans of the H80i system. It also allows you to see what it is doing and to configure it. So within Corsair Link, observe what it says its radiator fan and pump speeds are. Then look closely at the configuration options for the radiator fans. I fully expect they will be set to use DC Mode (they may not even have an option, since they are designed for use with the 3-pin fans supplied). Then look at other options. It should be set to use Automatic control, not to use full speed all the time. And its fan curve should be set to some normal default curve.

With Corsair Link installed and working, your mobo's CPU_FAN control system will NOT do anything for those fans. All the control of the H80i system is through Corsair Link. BUT that can only work if all of its connections are done right. I suspect you may not have had the cable from the pump body to a mobo USB2 header in place; that would prevent the Link software from communicating with the H80i system, and its default behaviour in that case would be to give you full cooling to ensure the CPU is OK.