2 Iron

Re: XPS-15-9570 (Bios 1.7) -

@Renx-78 What Windows version are you running? Type in winver in search/cortana. The freeze/lag you described "before fans turning on" is actually the typical famous Optimus (the automatic switch between the integrated Intel to the Nvidia GPU) freeze/lag, which was "fixed" some time ago actually "officially". It was never really fixed, but MS reduced the lag, so you wont notice it anymore that much, it is still present though. Read about it all here:

The fan issue described in this thread basically is connected to the Optimus switch bug, but Dell is incompetent and doesnt seem to understand, what is going on here, where it is crystal clear and simple.

The incompetent Dell devs changed the fan logic with 1.7.0, that the moment the dGPU gets triggerd, the fans turn on. This was already kinda happening before 1.7.0  randomly, but with a way lower trigger chance. I think, the EC logic before 1.7.0 worked like, that the EC was checking for dGPU activity every x seconds, maybe every 2000ms or something. So that manifest into the fans randomly going on too before 1.7.0, but way way less. With 1.7.0 they seemed to have lowered the check rate dramatically, to something like miliseconds, or maybe 100ms or something. So it checks every 100ms, if the dGPU is "on".

The problem is now the Optimus bug, which is still present in Windows 10. You can actually see it happening, if you open HwInfo and double click on the dGPU temp sensor reading and just let it log in the background. If you then just go around and use Windows, the dGPU gets activated for just a few milliseconds randomly. It then looks like this:

And THIS is now triggering the fans up from 1.7.0 all the time.

Dell is incompetent. The Optimus bug can easily be reproduced on all kinds of Nvidia laptops. I am actually speaking to Nvidia support right now, if there is some hope they could fix this, but they dont seem to be interested in looking into it.

There are at least three different bugs with Optimus as I see it.

- the right click menu DLL hook is bugged, and triggers the dGPU randomly. deactivating the "show run as GPU processor" hook in the Nvidia panel, deactivates this trigger actually at first, but it will come back (I dont know why but it does, even with the hook off)

- the Optimus switch is bugged, at least on the XPS 15. it triggers / polls the dGPU for no reason randomly all the time, maybe just on the 4k model because of a too low trigger value of GPU activity, and Optimus tries to shift over to the dGPU.

- the Optimus Override is bugged and doesnt work properly.

Dell has to revert back the change they secretly made with bios 1.7.0.

I dont care they acknowledge their mistake. For me, they can lie as usual and deny there is an issue, but secretly fix/revert it back with an upcoming bios. But knowing Dell, they dont care and wont revert a mistake they did.