H115i fan rpm reporting

Hi,

I've just installed H115i on my system, replacing H110, and I'm noticing a odd behavior regarding pump/fan rpm reporting. The BIOS for CPU and CPU_OPT fan headers are set to normal. The H115i is using 4 SP140's in push/pull configuration as intake at the top of the case. The SP140's are attached to the fan hub and pwm cable from the fan hub is plugged into the CPU fan header. The H115i's cable is plugged into the CPU_OPT header. All other fans (2 intake in front, 1 exhaust) are also plugged into the fan hub. Also, the fans are controlled by speedfan with a curve instead of using Corsair Link.

Upon booting up the system, I went into the BIOS and shows 2 fan speeds. The CPU fan is at 650 rpm and CPU_OPT is at 1460'ish rpm. Since I've plugged all the radiator fans to the fan hub, is the CPU_OPT reporting the pump speed? I've set the H115i to performace mode as well.

TIA.

JB

is the CPU_OPT reporting the pump speed?

No, the only way to read the H115i pump speed is via the USB connection.

I thought so. So my question is what IS the rpm that is being reported in BIOS for CPU_OPT header? According to the manual, the CPU_OPT header is for water cooling CPU fan header. Can I just unplug the fan header from CPU_OPT?

JB

So my question is what IS the rpm that is being reported in BIOS for CPU_OPT header?

Good question and the short answer is I don't know. With my H80iGT the Fan 1 speed and CPU Fan speed are about the same, but I have had reports and seen posts when they are different such as the one below from an ASUS X99-A system.

Were it my system I would log a call via https://corsair.secure.force.com/home/home.jsp and ask why the two speeds are different as Corsair no longer seem to provide any information via this forum.

I see. Thank you for the information. I will ask Corsair as well as Gigabyte. In the meanwhile, I unplugged the connection from H115i to the CPU_OPT header. I verified that the pump is still running in the performance mode with the Corsair Link software. The system is running very cool (27C on idle and very quiet since the rpm's are around 700's) and the fans ramp up as the CPU temps rise.

One more question. Does the pump speed increase as the CPU temps increase if I don't have the Corsair Link software running in the background?

JB

Does the pump speed increase as the CPU temps increase if I don't have the Corsair Link software running in the background?

No, further even if CL4 is active AFAIK this is not possible and CL4 can only set the pump to either silent or performance mode. Check the CL4 pump configuration panel.