I registered just to post this, because in 2021 this issue still plagues the program. Having installed the Ryzen balanced power plan, I was disappointed to see the Corsair service causing high CPU usage, in my case from Corsair.Service.exe. The issue has followed me through several versions of the program. It's very frustrating since it keeps the CPU running at high clock speeds, and keeps the CPU running at about 52 C because it's under a constant load of about 10%. This is with a H115i, it really shouldn't be getting this hot unless something is constantly using the CPU, and iCue is doing it.
This is caused by the plugins for the program. It can be fixed by renaming/deleting the "Plugins" folder within the iCue folder. Once I have done this, iCue can still get temperatures from my motherboard (I don't really care about this) and is functionally exactly the same, it just doesn't cause high CPU usage, high power usage for the machine and high CPU temperatures any more
