10-30-2018 08:27 AM - edited 10-30-2018 11:48 AM
I'm using an X1E with an external monitor connected to a Thunderbolt 3 Workstation Dock via DP and the laptop will only use the Nvidia GPU. There's no apparent option to run switchable or internal GPU. Is there any way of changing this and forcing it to use integrated? I really don't want the machine constantly running hot with the fans going if I'm just doing office work and have no need for the dGPU.
11-13-2018 01:50 PM - edited 11-13-2018 11:27 PM
Just out of curiosity, if you disable the Nvidia GPU in the device manager, does the dock's display output still work? It's not outside of the realm of possibility that some display outputs were connected to the Nvidia GPU.
If I recall correctly, the Intel IGP only supports 3 outputs. One is used by the internal display, but the laptop has three more video outs (2x TB3, 1x HDMI). This means at least one of them is likely connected to the Nvidia GPU, unless if switches were used.
Intel IGP's DP 1.2 is only sufficient to support one 4K display at 60Hz. Meanwhile, the Nvidia GPU has DP 1.4, which can support two 4k displays at 60Hz (newer gen TB3 controllers support DP1.4 passthrough). To me, it seems likely to me the Nvidia GPU is driving the TB3 dock's video outputs. But this is just a guess from me.
12-23-2018 10:28 PM
Has anybody managed to force to use the integrated GPU while docked? I have tried disabling the NVidia adapter in device manager, but it simply results in the external display not working I hope this option becomes available soon.
12-24-2018 11:37 AM
Do you have the Nvidia control panel installed? As a test, remove the X1 from the dock and then right click a graphic app. 2nd line in the dropdown menu should be 'Run with graphic processor'. Clicking that and you get the choice... Intel or Nvidia. If you don't see that dropdown, get the Nvidia control panel off the Lenovo site. Maybe the Nvidia control panel app will also work when docked.