Three Questions about Corsair H115i, PLEASE HELP!!

[zihanzzz]

Hi guys, I recently purchased a Corsair H115i liquid cooler for my Intel 7700K. I have the following questions which are really bothering me before I even attempt to start building my PC. Please shed some light, thanks!!

1. The manual didn't mention how to plug in the SATA cable that comes out of the pump. Should I plug it in? If yes, does it go to my mother board or does it go to my PSU?

2. There are two fan connectors coming out of the pump. One of them has 4 pins, the other one has 3 pins. What is their difference? Does it matter which fan connects to which? I want to understand the technical difference : )

3. The manual mentions two kind of very similar standoffs, the LGA 115x /1366 Standoff and the AMD BLACK STANDOFF. Please see the picture below. I am going with LGA 1151, should I choose the standoffs above? Besides color difference, the black ones (I'm assuming they are for AMD) have different threads on each side.

Please comment if you know the answers! Thanks a lot!!!!!!

 

[Aeacus]

Q&A

1. The SATA from AIO plugs into your PSU and is used to power the pump and it's connected fans.

2. 3-pin fan header is missing PWM pin and fan connected to there doesn't send it's RPM signal back to Corsair Link. Instead, Corsair Link reads the RPM value of the fan which is connected to the 4-pin fan header.

My guess is that Corsair deliberately removed the PWM pin for 2nd fan, so that Corsair Link software won't be confused by 2 different RPM signals.

As far as fan connection goes, it doesn't matter which fan you plug into them. Though 4-pin PWM fans are preferred since both fan headers have 4th pin for PWM control of 4-pin fans.

3. That i don't know. Best solution: trial and error. Just try with one standoff if it goes into MoBo or not. Take the wider threaded standoff and try to screw it in. If MoBo accepts narrower threaded standoff then the wider threaded standoff won't go in.

Btw, nice pics. Those help a lot to diagnose your worries.

 

[zihanzzz]

Hi Aeacus, thank you very much for your detailed explanations. Love them!
One quick follow-up question on No.2, I think Corsair Link can control the speed of the fan(s). Having only 1 fan has RPM, does that mean only 1 fan can be speed-controlled? Or is the fan speed somehow synced between the two fans? Thanks!

 

[zihanzzz]

Actually, I found the following paragraph from Wikipedia:

"Fan connectors
The common cooling fans used in computers use standardized connectors with two to four pins. The first two pins are always used to deliver power to the fan motor, while the rest can be optional, depending on fan design and type:

Ground – common ground
Power – nominally +12 V, though it may be variable depending on fan type and desired fan rotation speed
Sense output from fan – outputs a signal that pulses twice for each rotation of the fan as a pulse train, with the signal frequency proportional to the fan speed
Control input – a pulse-width modulation (PWM) input signal, which gives the ability to adjust the rotation speed on the fly without changing the input voltage delivered to the cooling fan
The color of the wires connected to these pins varies depending on the number of connectors, but the role of each pin is standardized and guaranteed to be the same on any system. Cooling fans equipped with either two- or three-pin connectors are usually designed to accept a wide range of input voltages, which directly affects the rotation speed of the blades."

I think both fans are speed-controlled by the 4-th pin (PWM). Only one of the fans have output (speed report).

 

[Aeacus]

I think both fans are speed-controlled by the 4-th pin (PWM). Only one of the fans have output (speed report).

Yes, you are correct.

Though, do note that when you plug 3-pin fan into the fan headers then only way to control fan speeds is by DC mode and not PWM mode.
DC mode = adjusting input voltage.

 

[zihanzzz]

I think both fans are speed-controlled by the 4-th pin (PWM). Only one of the fans have output (speed report).

Yes, you are correct.

Though, do note that when you plug 3-pin fan into the fan headers then only way to control fan speeds is by DC mode and not PWM mode.
DC mode = adjusting input voltage.

Thanks. If I plug in 3-pin into CPU_FAN (motherboard) and the Corsair LINK USB, can I still use the Corsair LINK software to control fan speed (I think Corsair LINK uses PWM?)? I think the installation guide told me to plug in both.

 

[Aeacus]

The 3-pin wire from AIO to CPU_FAN header is for MoBo to know that you have a CPU cooler in place. You'll also need to connect the USB cable so that Corsair Link can detect your AIO and you can control the rad fan speeds via Corsair Link.

 

[zihanzzz]

The 3-pin wire from AIO to CPU_FAN header is for MoBo to know that you have a CPU cooler in place. You'll also need to connect the USB cable so that Corsair Link can detect your AIO and you can control the rad fan speeds via Corsair Link.

Thanks. When you say if I plug in 3-pin fan into fan headers the only way to control fan speed is by DC mode, that's without USB, right? If I additionally connect USB, then I can do PWM?

Sorry for the spam. I just want to understand the whole thing before I plug the in : )

 

[Aeacus]

You'll need Corsair Link to control your rad fans regardless if your rad fans are 3-pin and use DC (voltage) control method or 4-pin and use PWM control method.
Without USB cable between AIO and MoBo, Corsair Link can't detect your AIO and you can't control your AIO at all, including rad fans.
Oh, if you don't connect the USB cable then by default, Corsair AIOs are programmed to run in "performance" mode. This means that pump and rad fans operate at maximum capacity all the time (great for cooling but extremely noisy as well).

Btw, you're not spamming. Asking additional questions relevant in the topic are welcome and i'm happy to give you answers if i can.

 

[zihanzzz]

You'll need Corsair Link to control your rad fans regardless if your rad fans are 3-pin and use DC (voltage) control method or 4-pin and use PWM control method.
Without USB cable between AIO and MoBo, Corsair Link can't detect your AIO and you can't control your AIO at all, including rad fans.
Oh, if you don't connect the USB cable then by default, Corsair AIOs are programmed to run in "performance" mode. This means that pump and rad fans operate at maximum capacity all the time (great for cooling but extremely noisy as well).

Btw, you're not spamming. Asking additional questions relevant in the topic are welcome and i'm happy to give you answers if i can.

Thanks. It sounds like I will just plug in everything:
1. SATA power cable to my PSU
2. Fan connectors to my two fans (one 3-pin, one 4-pin)
3. Corsair Link USB
4. From Pump to CPU_FAN header

Then I should be using PWM to control my two fans. In this configuration, I am not using DC control method, right?

 

[Aeacus]

Fan control method depends on how many pins (wires) the fan has. The stock SP140L PWM fans included with the AIO are 4-pin fans and they support both, PWM and DC control. As far as in which control mode your fans are, that you have to check within Corsair Link.

 

[zihanzzz]

Fan control method depends on how many pins (wires) the fan has. The stock SP140L PWM fans included with the AIO are 4-pin fans and they support both, PWM and DC control. As far as in which control mode your fans are, that you have to check within Corsair Link.

Sure. Thank you.