Corsair h100i v2

[johnmiami6315]

Does the cpu fan cable that comes from the pump need to be plugged into a cpu fan header or can it be a system fan header? I think it can be on the system fan header since my current air cpu cooler is plugged into those, but I would like a second opinion.

 

[devbiker]

It can be on any header as long as that header is set to 100%/full speed. The cooler requires the full 12V at all times. This is incredibly important and not included in the installation instructions.

Putting it on the CPU_FAN header provides a tach signal to prevent the CPU_FAN BIOS warning at startup. And if you do get it, it means that the pump is dead.

 

[Paperdoc]

It is much better to connect the pump to the mobo CPU_FAN header. In fact, your old fan should have been there anyway, for two reasons:

(a) the CPU_FAN header always uses for its guide the temperature sensor inside the CPU chip, and that always should be how the CPU chip cooler is guided. If you use a SYS_FAN header instead, and IF it has the option, and IF you actually do this configuration setting, you can force that header to use the CPU chip sensor. Otherwise, that header will try to guide the fan according to a temperature measured on the mobo.
(b) FAILURE detection. Most mobo headers will monitor the speed signal from their fans for failure of the fan, and send a warning when it happens. Most mobos do much closer monitoring for failure of the CPU_FAN fan speed. If it fails, often you get a warning for a short time that is quite prominent, and then the entire system shuts down without even waiting for the CPU's internal temp sensor to signal high temperatures. This is to prevent possible damage to the CPU chip. But if the actual CPU cooling system (whatever that is) is connected elsewhere, the mobo cannot do that job!

When you connect the fan cable from the H100i pump unit to the CPU_FAN header, the header will receive the pump speed. The pump motor will receive a full +12 VDC supply on Pin #2 at all times if the header is configured to operate in PWM Mode, even though the pump connection is of the 3-pin type. It is supposed to be fed that way. THEN the connection from the pump unit to the fans on the radiator will alter the speeds of those fans according to the CPU chip's internal temperature, and that's how CPU cooling is controlled. To make this work properly, you also need to connect the cable supplied from the pump unit to a mobo USB header, AND download and install the Corsair LINK utility. IT is the software that does control of the rad fans to match internal CPU temperature, using the USB cable for communication. The utility can show you a bunch of info and allow you to custom-configure some settings, too.

 

[Paperdoc]

Thanks for Best Solution.