Question Corsair h115i push/pull

Feb 10, 2021
I have a Corsair h115i in a push/pull config, but they aren't plugged in corectly, the fans that came with the aio are separate from the other two i added on top. The build wasn't done by me and even though i told the guy to have them installed together so that they have the same speed ,he didn't do it.... 2 fans i have to control from the BIOS and two from the iCUE software, so i can't really have them at the same rpm. My question is, what do i have to do to have them connected together?


Connecting four fans to the two outputs from the pump on a Corsair H115i system will require a bit of investigation, and you may NOT find the clear answers. The issues are: what is the maximum current draw of all your fans, and does that meet the limits of output from those fan feeder connectors? For the fans, you may be able to find specs OR read from labels on the fans the max current draw of each. But sometimes you can't find that. For the limit of max current output from the pump feed cables, I have never seen Corsair tell us that info. Most mobo headers can supply up to 1.0 A max, but I would NOT bet that the H115i's outputs can do the same unless you can get Corsair's Tech Support people to give you the real specs. Without all of that info gathered and able to verify that this is safe, you can NOT use simple Splitters. because their ONLY source of power for the fans is the outputs from the pump unit.

The much safer alternative is a fan HUB, which is a different device. A HUB gets all power for its fans from the PSU directly via a cable to a PSU SATA power output connector, so it draws no power from its host fan header (in this case, the pump output cables). The hub does REQUIRE that the host header operate in PWM Mode to supply the PWM signal it can distribute to its fans, AND that the fans it supplies be 4-pin PWM models, not 3-pin. Now, the H115i system says it comes with 4-pin PWM type fans for the rad, so it is reasonable to assume that the pump outputs are operating in PWM Mode. Then you, OP, would need to be sure that the fans you ADDED also are of the 4-pin PWM type. If those conditions are met, then using a HUB is the safe and sure way to do this. An example Hub:

Any fan header can deal with the speed signal sent back to it from only ONE fan. So any Splitter or Hub will only send to its host header (or in this case, a fan output connector from the pump) the speed of ONE of its fans. So the Splitter or Hub will have one output connector marked in some way - in the case of the SilverStone example I linked above, one output has a clearly-marked box around it. For you, OP, ONE of the rad fans - preferably one of the Corsair fans supplied - must be plugged into that Hub port. ALSO note that, of the two outputs from the pump unit, one will have four pins in it, and another will be missing its Pin #3. Plug the cable from the Hub into the output that has ALL four pins. This way the speed of one of the rad fans will be fed to the Hub and then relayed back to the pump, where Corsair's iCue software utility can read it and verify the fan speed.