I found this thread after narrowing down the issue of buggy iCUE software downgrading what should have been an upgrade to my cooling system. I just bought a Corsair CPU block, GPU block, pump/res and a Commander Pro to manage it all. After installing everything yesterday I ran Heaven and immediately noticed the stuttering and massive drop in FPS others have reported. I eventually ran CPU-Z and saw the incredible drop in single core performance others here have posted about.
Since this bug results in a CPU issue, it impacts everything we do on our system. High FPS games that are CPU bound are severely impacted. Once you push the graphics settings up and shift the burden to the GPU the symptoms are less severe, but still impact performance. Synthetic tools make it easy to diagnose (CPU-Z, Cinebench).
Completely uninstalling the iCUE software returned performance to expected levels. Unfortunately, it took a number of other steps before I narrowed the problem down to iCUE and got rid of it.
I'm surprised Corsair hasn't pulled down the buggy version of iCUE, instead risking those of us who have high end systems and lots of disposable income returning hundreds of dollars worth of their hardware because of their free, buggy software. I'm especially surprised since earlier in this thread they reported they can replicate the problem and have a root cause. I guess they've done the math and they'd rather lose sales from a few of us who spend lots on their hardware than offer a known solution to a known problem.
System Specs for the record
ASUS ROG Maximus X Hero Wi-Fi - Z370
i7-8700K (Corsair XC7)
32GB Corsair Vengeance RGB PRO (CMW32GX4M4C3200C16W)
EVGA 2080 Ti (Corsair XG7)
Corsair XD5 pump/res
Corsair Commander Pro
Still considering returning the cooling hardware as it doesn't work as it should without the iCUE software. I can pick another set of blocks and pump/res that will work with the rest of my hardware / software easily enough. I can't wait until the end of the month on a "maybe" from Corsair.
