Have a new Latitude 7400 with i5-8365U and when there is nothing going on - no application opens, the CPU is sitting at 2.40-3.0Ghz per Task Manager. I would expect it to be <1Ghz. I think that is causing the fan to kick on (albeit pretty low) but it's annoying. Annoying to the point where I want to return the machine after 48 hours.
I checked and I only see 'Balanced' power plan available.
Went to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power on the right, one of the keys near the top should be called CsEnabled. Changed the value of this key from 1 to 0. Got all the power plans back after a reboot. I set the power plan to Power Saver and saw the CPU throttle down to 0.87 and 1.43Ghz. Much better and after a bit the fan turned off.
I exported the Balanced setting from my XPS 9370 (where throttling works just fine) and imported on the Latitude 7400 then applied it. Watched the CPU climb back up to higher speeds and the fan kick on, machine get warm, etc.
I'm thinking this might be beyond Windows 10.
Did it make it any better because I have a 7300 which is having the same issues. Its very strange, if you stress test the CPU it actually runs cooler because the cores are not boosting as high.
Open the task manager and what processes cause the issue.
Open additional power settings and change the settings to improve battery life. Just type "Additional Power settings" in the search box beside Cortana.
Update the firmware and other driver updates to ensure that the issue is resolved.
I found a simple solution using a cold pack directly from the freezer. I put the 7400 on the cold pack and after 20 seconds the fan stopped. Probably it willl start again when the cold pack reaches room temperature, but then I will swap it with a fresh one from the freezer. Works in the home office. Not a great solution for the road off course
probably They can make some BIOS modification that make CPU less warm but opposite of this the laptop can achive less efficiency. I think this is only one way in this situation . This model should have more efficient cooling system and this is the main problem. Warm Air flow should have less resistant and go out not to bezel of screen but maybe on the side of laptop ? Radiator should be about 20% bigger, fan too..ehh something went wrong in engiennering process i think and this is my opinion. But this times make big competition between lenovo,dell,hp,acer, and others and they still experiment with solutions that are not necessarily the best for the end user.