daknetworks.com

Discrete Graphics / Switchable Graphics

It can be confusing as there are many variables here with different definitions. By default, the Precision 7720 has both an Intel onboard graphics chip and an added graphics chip (Nvidia/AMD; aka discrete-graphics). By default, the onboard chip is on as the primary graphics. This is true when using the laptop monitor, when a docking station is used and when a monitor is plugged directly into the laptop’s DisplayPort, HDMI connectors, and Thunderbolt/MiniHDMI port.

Dell calls this switchable-graphics. Disabling this must be done in the bios. If you have switchable graphics disabled, the onboard Intel GPU is not used.

With the "Discrete graphics controller direct output mode" or “Graphics Special Mode”, the external ports (DisplayPorts, HDMI connectors and Thunderbolt/MiniHDMI port) will be driven by the GPU directly.

Click here to see:

https://www.dell.com/support/article/us/en/04/sln304550/precision-7510-7710-graphics-special-mode-setting-in-the-bios?lang=en

In short:

• -enter bios
• -disable switchable-graphics.
• -enable special-graphics mode.
• -enable dock-display-port

Dell Dock

To make it more confusing, the WD15 dock with 130W adapter is not powerful enough for a Precision 7720 with discrete-graphics. A 180W adapter is needed with the WD15 or if you are using a TB16, you would need a 240W adapter.

Lastly, there are special drivers/firmware that are needed to make the USB-c supply the correct power. The following must be updated:

• -Thunderbolt Controller Driver
• -Thunderbolt 3 Firmware Update
• -ASMedia USB 3.0 Extended Host Controller Driver for Dell Thunderbolt Dock
• -RealTek USB GBE Ethernet Controller Driver for Dell Thunderbolt Dock
• -RealTek USB Audio Driver for Dell Thunderbolt Dock

Click here to see:

https://www.dell.com/support/article/us/en/04/sln301075/how-to-use-and-troubleshoot-the-dell-thunderbolt-dock-tb16-?lang=en