I'm no expert in the matter, but then again, neither does Fan Xpert seem to be, as I've got my AIO pump curve set to 60% until 60c, then gradually increase to 100% up to 75c and, hopefully, never beyond.. but the software doesn't seem to want to update it properly.
I've attached a screenshot of my pump settings, but didn't think to screenshot it while it was screwing up. I'll update here with it next time it does it. When glitching, it'll be at the idle portion of the curve, somewhere before the 60c mark, but the orange dot isn't attached to the curve line─instead, it'll be up at 100%:
Often times (every day) when the CPU is at 38-50c during idle (browser, movies, etc.), the software doesn't drop the pump speed down, and it stays stuck at 100% after gaming. I'll hear it cranking over there while I'm using the browser, and notice it's sitting at 38-40c, but shows the orange indicator dot up at 100% anyway. I have to change the base 60% speed up or down and Apply it to make it update and drop to the selected speed. Then I just change it back to 60%.
It seems to do this most often when I first boot into Windows, or after gaming. It's like it just gets stuck at 100% for some reason because the software fails to update it. I'm not running any other fan control software, so there shouldn't be any interference.
I guess I'm here to see if anyone has a workaround? I've seen this same issue with Gigabyte's fan control software, and fans not dropping down to preset idle speeds, so it seems like an issue across multiple fan control software suites, or perhaps an issue inherent in Windows. Could it be the BIOS settings fighting with Fan Xpert? No idea, but that's why I'm here.
UPDATE: Something I've realized is that the pump in this AIO is not PWM, so the BIOS doesn't allow for adjusting the pump curve like the software does. It just doesn't give the option for DC voltage control of the pump speed, so the pump is maxed out at 100% until Fan Xpert takes over. I created a new Fan Xpert profile and it seems I've at least been able to get the pump to start at the preset speed at the start of Windows, so that's a plus. It still gets stuck sometimes on startup, but not as often. Still gets stuck sometimes after gaming, but, I guess I'll have to live with it until I find a fix. If I find one.
• Ryzen 3900X @ 4.3GHz All Core (1.325 vcore)
• Cooler Master MasterLiquid LC240E AIO
• 32GB Corsair Vengeance RGB Pro DDR4 3600 RAM (16-18-18-38)
• EVGA RTX 2080 Black GPU
• 2 x Sabrent 500GB PCIe Gen 4 NVMe M.2 (raid 0)
• Samsung 860 4TB SSD
• WD Black 8TB HDD
• EVGA SuperNOVA 850 P2 PSU