precision 5750 disable iGPU in bios

@RuiRuiRui  The Precision 5750 is the sister system of the XPS 17 9700.  On the latter system when configured with an RTX GPU, there is a BIOS option to have the NVIDIA GPU take direct control of all display outputs, including the one driving the built-in display.  I don't know if this completely "hides" the Intel GPU at a hardware level since the Intel GPU is built into the CPU, but it does prevent it from being actively used since it's no longer driving any displays.  But you should know that doing this will impose a battery life and possible noise penalty, since in that configuration the NVIDIA GPU will be active all the time, even when nothing graphics-intensive is going on.  That means it will be drawing power and generating heat (which will require more fan activity for cooling) all the time.

Is this option available for Precision 5540? I can't find it in the BIOS.

@chepalle  I don't believe so.  The Precision 5540 is the sister system of the XPS 15 7590, which didn't have this option.  In fact even the newer XPS 15 9500 launched alongside the XPS 17 9700 doesn't have this option, and as mentioned above, even on the XPS 17 9700, the option only exists on systems ordered with an RTX GPU, not a GTX GPU.

Received the machine.

For those who are interested in running linux on precision 5750:

(1) The 'Direct Graphics Controller Direct Output Mode' in bios is not the same thing as "'discrete graphics'/'hybrid graphics'". 'lspci | grep VGA" can still see the iGPU and you have to use prime-select in linux to select which GPU to use. Enabling 'Direct Graphics Controller Direct Output Mode' in bios does eliminate 4k video lagging.

(2) make sure you create a recovery ISO before changing ssd, the factory ubuntu 18.04 works fine with the hardware. if you switch to ubuntu 20.04 the sound will not work, there are tutorials online about how to get it work. I just simply revert to factory 18.04 from the ISO to save the trouble.

(3) I have dual boot windows 10 and ubuntu 18.04. The sound quality in windows 10 is much better than that in ubuntu, should be driver related. The 4k screen is gorgeous.

(4) tested power adapter maximum power supply, it can pull 132.8w.