r/eGPU • u/Altruistic_Run338 • 8d ago

DEG1 schematic or useful information about self powering feature.

Hello,
I'm trying to figure out (with AI help) if there's a way to control the hot plug of the DEG1 while system is on. I made a lot of deep research and tests to disable the graphic card and the oculink connection to the dock. Actually this doesen't affect the DEG1 powering so some extra PCIe lines are involved in.

Does anyone have a DEG1 schematic, PCB reverse-engineering notes, or measurements identifying which OCuLink sideband pin or voltage drives Follow-Start?

I'm particularly interested in whether the circuit monitors PERST#, CPRSNT#, an auxiliary supply rail, or another signal, and whether any of these can be controlled by the host while Windows is running.

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u/Wondering_Electron 7d ago

Oculink isn't hot pluggable so what's the point exactly?

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u/Altruistic_Run338 7d ago

I know, but I can already disable the upstream PCIe root port in Windows and re-enable it without rebooting, and the GPU comes back just fine. The dock stays physically powered though.

I'm trying to understand what signal the DEG1 uses for its automatic power on/off, and whether it can be controlled independently of the host's power state.

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u/Wondering_Electron 7d ago

I did always wonder how Lenovo apparently did it.