AIO liquid cooler plug into cpu header or water pump header

[aalex2]

Hi,

I recently bought a corsair h100i v2 cooler, and I'm wondering which header to plug the pump into. I know that in the manual it says to plug it into the CPU_FAN header, but my motherboard has a dedicated water pump connector (the ASUS Z170-A).

I'm wondering if I should plug the pump into that water pump header and leave the CPU Fan header blank. Will it cause any problems to plug the pump into this water pump header, leave the cpu fan header blank, and still plug the radiator fans into the plugs coming from the water block?

Thanks in advance!

 

[CountMike]

If it has it, use it or loose it.

 

[Dar_BB]

Not really a solution, but I am having the same question. I have a Silent Loop, which has two 280mm fans that connect to my ASUS X99A-II MoBo via a y-cable. I have them connected to the CPU_FAN connection. I have the pump connected to CPU_OPT and appears to be working and the PUMP runs at a constant 2200 PRMs. However, I am wondering too, if I should use the W_PUMP connection.

 

[CountMike]

You mean two 140mm fans ? Yes, pump should go to a place where it should get constant voltage. Pump should turn constant speed and fans on radiators could be regulated by CPU_Fan so they change speed according to CPU temperature. Some WC cooling systems have also USB connector over which SW can regulate all speeds. It's also good to have pump on a connection that can detect it's speed and raise alarm if pump would stop. Just a safety feature.

 

[Karadjgne]

Here's the skinny. Corsair AIOs include basic instructions that are so generic they'll apply to any mobo made. Corsair recommends installing the pump to the cpu_fan header for 1 simple reason, the pump will usually fail before the fan and mobo's have a failsafe to protect the cpu. Mainly, if there's no rpm registered on the cpu_fan header, the pc won't boot or shuts down immediately. So if the pump fails, the pc is supposed to shut down. However, on basic AIOs this leaves temp control at the mercy of a sys_fan header, which has different temp setups from a cpu. Most cases don't ever reach past 40°C whereas cpus can easily hit 70°C.

The h100i doesn't use the cpu_fan header for temp control, it uses the USB cable and Corsair Link software, so with that method, as long as 'something' is plugged into the cpu_fan header, all good.

Personally, my system is contra recommended, the rad fan is on cpu_fan and the pump is on cpu_aux which is a non-controlled straight 12v so I have temp regulation, volume and speed control of the fan and still have max pump performance, which is what most AIOs need, not a variable speed pump.

You will absolutely need something plugged into cpu_fan or the pc will not boot. Having a dedicated header for cpu_pump just sets basic AIOs up same as mine, but being an advanced AIO, your actual power is supplied differently, but still needs to read the tach wire as having actual rpm, thereby the mobo assumes there is a working cooler attached to the cpu.

 

[CountMike]

Good explanation.

 

[aalex2]

Here's the skinny. Corsair AIOs include basic instructions that are so generic they'll apply to any mobo made. Corsair recommends installing the pump to the cpu_fan header for 1 simple reason, the pump will usually fail before the fan and mobo's have a failsafe to protect the cpu. Mainly, if there's no rpm registered on the cpu_fan header, the pc won't boot or shuts down immediately. So if the pump fails, the pc is supposed to shut down. However, on basic AIOs this leaves temp control at the mercy of a sys_fan header, which has different temp setups from a cpu. Most cases don't ever reach past 40°C whereas cpus can easily hit 70°C.

The h100i doesn't use the cpu_fan header for temp control, it uses the USB cable and Corsair Link software, so with that method, as long as 'something' is plugged into the cpu_fan header, all good.

Personally, my system is contra recommended, the rad fan is on cpu_fan and the pump is on cpu_aux which is a non-controlled straight 12v so I have temp regulation, volume and speed control of the fan and still have max pump performance, which is what most AIOs need, not a variable speed pump.

You will absolutely need something plugged into cpu_fan or the pc will not boot. Having a dedicated header for cpu_pump just sets basic AIOs up same as mine, but being an advanced AIO, your actual power is supplied differently, but still needs to read the tach wire as having actual rpm, thereby the mobo assumes there is a working cooler attached to the cpu.

Thanks for the reply!

So based on what you're saying, It'd be fine if I were to plug my radiator fans into my CPU_FAN headers (I have two cpu fan headers, so I could plug both radiator fans into those), and then I could use the dedicated water pump header for the pump, even though that isn't exactly what the manual says? Do you know if there would be any problems in this setup?

 

[Karadjgne]

Ty. When I first set up mine (wife's actually) I did as corsair recommended. Being a 3pin, the pump ran at a constant rate, the cpu_fan header is dedicated pwm not analog, you need a 4pin for any control. This set my fan at always at 100% since the cpu was well over 40°C at anything beyond idle (i5-3570k @4.3GHz). Asus fanXpert was great for getting that all sorted out, but I still didn't get honest cpu temps. So the headers got switched. FanXpert is great on that it has alarms. Since even at 100% load on p95 26.6 small fft the temp doesn't go beyond 70°C for any reason, I set the alarm for 72°C. Now if the cpu overheats it's one of two things, pump failure or time to clean the radiator. Simple.

 

[cherylC]

Ty. When I first set up mine (wife's actually) I did as corsair recommended. Being a 3pin, the pump ran at a constant rate, the cpu_fan header is dedicated pwm not analog, you need a 4pin for any control. This set my fan at always at 100% since the cpu was well over 40°C at anything beyond idle (i5-3570k @4.3GHz). Asus fanXpert was great for getting that all sorted out, but I still didn't get honest cpu temps. So the headers got switched. FanXpert is great on that it has alarms. Since even at 100% load on p95 26.6 small fft the temp doesn't go beyond 70°C for any reason, I set the alarm for 72°C. Now if the cpu overheats it's one of two things, pump failure or time to clean the radiator. Simple.

[Great post, Karadjgne! Hope you don't mind if I follow up? I have an Asus Maximus Hero IX board and plan on using the Corsair H100i v2. I was going to just connect the fans on the radiator together, and plug the pump into the AIO header. I wasn't going to use the USB. What do you mean when you said "the headers got switched"? You indicated your solution was to hook up the Rad fans up to the CPU fan header, and the pump to the CPU Aux, which would be the CPU_OPT connection on my board I assume. Did you switch the header connections? Did you have the USB connected for the pump? I only have one USB connector on my board. If I use it I can't hook up the one on the front of my computer.

I think I might have bit off more than I can chew. I have a be quiet dark base pro 900 case, and am still trying to figure out how where I should hook up the PWM cable from their case fan hub. 🙂

Thanks!

 

[CountMike]

USB is just for control and to transmit data to the system. It comes with a utility for that.

 

[Karadjgne]

There's basically 2 different types of aios, software controlled, usually by USB, and hardware controlled by motherboard and bios. The h55 I have is the second one, there is no USB hookup. The h100i series you have is the first kind. However, it's also backwards compatible, so if you choose not to use the Corsair link, and want a standard bios 'set and forget' then you can. You can do it as standard Corsair's instructions, with pump on cpu_fan and fans elsewhere, or you can fans on cpu_fan and pump elsewhere, but you'll still use the supplied Sata for power, the tach on the 3pin giving you rpm. This'll necessitate that in bios you set that particular header to 100% duty cycle, which maxes out pump speed, permanently.

 

[cherylC]

There's basically 2 different types of aios, software controlled, usually by USB, and hardware controlled by motherboard and bios. The h55 I have is the second one, there is no USB hookup. The h100i series you have is the first kind. However, it's also backwards compatible, so if you choose not to use the Corsair link, and want a standard bios 'set and forget' then you can. You can do it as standard Corsair's instructions, with pump on cpu_fan and fans elsewhere, or you can fans on cpu_fan and pump elsewhere, but you'll still use the supplied Sata for power, the tach on the 3pin giving you rpm. This'll necessitate that in bios you set that particular header to 100% duty cycle, which maxes out pump speed, permanently.

Thank you for the answer. It will take me a bit to digest, but I think I understand what you are saying. In any event, you suggest I don't use the AIO connector on the Asus Her IX motherboard? The documentation says that header is 12w and the default speed is Full Speed, while the CPU_Fan & CPU_Opt headers, and the 3 Chassis Fan headers are 12W and Q-Fan Controlled.

I do prefer the set it and forget it.

Thanks!

 

[Karadjgne]

If you want to, you can use the pump 3pin on the cpu_pump and the fans on cpu_fan header. That's fine. Just as long as the cpu_fan header is populated by something. You won't be using much of any of that 12w (1Amp, which is standard) on the cpu_pump header as the actual pump itself is powered by the Sata power from the psu. That header will basically just be used for the tach wire, so in fanXpert you'll see the pumps rpm. I like fanXpert, a lot, it has this neat setting for alarms which many don't, so take a peak at what rpm the pump normally runs at, and set the alarm to go off if it drops 400rpm or so. The fans don't need an alarm, they are variable speed, and if the fan with the tach off the splitter reaches 0rpm,tbe pc will shutdown anyway because of the cpu_fan security.
On my Asus board, all headers are under Qfan able control except cpu_aux which is grayed out, it's 12v dedicated. Since your fans are pwm, you won't have an issue on cpu_fan header as that's a dedicated pwm header. You'll nerd a 4pin splitter for the fans, a 3pin won't work.

 

[Miketdavo]

If you want to, you can use the pump 3pin on the cpu_pump and the fans on cpu_fan header. That's fine. Just as long as the cpu_fan header is populated by something. You won't be using much of any of that 12w (1Amp, which is standard) on the cpu_pump header as the actual pump itself is powered by the Sata power from the psu. That header will basically just be used for the tach wire, so in fanXpert you'll see the pumps rpm. I like fanXpert, a lot, it has this neat setting for alarms which many don't, so take a peak at what rpm the pump normally runs at, and set the alarm to go off if it drops 400rpm or so. The fans don't need an alarm, they are variable speed, and if the fan with the tach off the splitter reaches 0rpm,tbe pc will shutdown anyway because of the cpu_fan security.
On my Asus board, all headers are under Qfan able control except cpu_aux which is grayed out, it's 12v dedicated. Since your fans are pwm, you won't have an issue on cpu_fan header as that's a dedicated pwm header. You'll nerd a 4pin splitter for the fans, a 3pin won't work.

Keep hearing this CPU_Fan must be populated rubbish from all over the place. If you try it you will get an error when posting stating the CPU! is Bla Bla Bla!, press F1 to get into bios, go to monitor, go to CPU and select {Ignore} from the drop-down,Your done! and you can now start your system without the CPU_Fan or Opt_CPU_Fan header populated. I do this all the time when setting up my AIO although in your case you'll probably find something to plug in there.

 

[CountMike]

You can but will loose control of fans according to CPU temp.

 

[Karadjgne]

Maybe. There is a work around to that, but it necessitates the usage of SpeedFan. With SpeedFan, you can set each header to supply power/pwm according to which ever address you choose. So you can set a sys_fan header to respond to cpu_fan temp address, or even set the cpu_fan header to respond to the gpu temp address, however you choose to do it. You'll then just tailor the fan curves to what output expectations you have. SpeedFan is the only software that'll do this, all others, including Asus fanXpert won't, they use default addresses. So if you use bios or fanXpert, then yes, you are stuck with no cpu temp control, if you use SpeedFan, you need to dig into it to get that all setup.

 

[CountMike]

CPU cooler fans are most important to control, first because they are largest and noisiest in whole system and with GPU fans, most important. I can't see no valid reason not to use them at CPU header. Newer MBs have BIOS options to "train" CPU and other fans for most economical automatic control. Each type of fan header has control by own sensor. This Asus of mine has 4. Even CPU1_Fan and CPU2_Fan are separately controlled so push-pull fans turn at different speeds for best performance.

 

[Karadjgne]

One of the advantages of having a newer gen mobo. Both of mine are z77's and the cpu_aux header is a 3pin constant 12v. Great for pumps, either low level aios or setup without using corsair link etc, where the fan is on cpu_fan header. But does mean that for big towers with double fans, either I pick 1 for a constant speed, maybe use a LP or ULP adapter, or run a splitter to cpu_fan and forgo usage if cpu_aux. Control would have been nice, but it has no addressable feature, so not even SpeedFan does anything.