in speedfan app click configure when options then check Enable DELL notebook support. when i did that i could configure the CPU and top case fans somewhat.  Its threshold is 60-70% and the fans are full speed or default, no happy medium . its annoying.   I like my 8930 but cooling is bad even after adding a 120mm dell Alienware fan and bracket and a separate front notuia fan to pull from the front and blow air in.   I also run a 850 watt seasonic PS.   
XPS 8940 with 11400 and 3060Ti. I upgraded the CPU cooler to a Noctua. However, when I try to check the fan curves using software like HWMonitor, HWInfo, MSI Afterburner, Speedfan, FanControl, none of them are able to detect CPU or case fan. GPU fans however can be detected and tuned no problem. Attached are some sensor information read from motherboard. Notice there is no CPU or case fan information.  Motherboard: DELL 0K3CM7. BIOS verision: V2.4, 2022-01-10   [IMAGE][IMAGE][IMAGE]
XPS 8940, 3rd party software cannot detect CPU or case fan