@everyone I advise to put stacked 3x1.5mm thermal pads on the PCH. This will dramatically reduce the temperature of the PCH, and has the nice side effect, that the fans wont come on under idle or Internet usage.
I have no idea, how incompetent Dell can be about this, and not pad the PCH.
The irony also is, that the XPS consideres the PCH temperature for its fans, even no air flow is happening on the PCH via the fans. And it has also a ridiculously low value triggering the fans at about 50°C.
Browsing the internet or watching a video will cause the PCH to rise to 48-51°C easily after a few minutes, and will trigger the fans. With thermal pads, it stays stable around 33-38°C under that work flow and no fans kick in.
This is totally a design flaw of the XPS.
You can cut them to the right size.
By setting PCI-Express to Maximum Power Saving in the Power Settings you should resolve PCH overhitting problem. I know that this is not an ideal solution but it worked for me.
I know is an old thread but was a definitive answer from dell given to this problrm? Also anyone was able to solve this. I have the pch temperature on my dell 9570 constantly at 80C, don't think is normal.