Alright guys, i think i have good news for everyone!
There is a new BIOS out (on the official website of SuperMicro) for the X11SCA-F, version 1.4.
I installed it and did following:
- Remove Quadro P2000
- Reset BIOS to default
- Primary Display : PCI
- Internal Graphics: Enable
- Switch off
- Build in Quadro P2000 again
- Start
- IPMI & Quadro P2000 works
So, now i can passthrough my P2000 to my Windows Plex VM AND use at the same time IPMI with all its features.
I did several reboots, disconnected the power cord and started again -> everything works! The last times it worked only for the first boot after setting it up as mentioned, now it seems to work always!
Have fun, maybe someone can double-check, if i don't have hallucinations.
EDIT1:
Okay, i ran again into the fault 43 state, but I think I could solve it.
Problem is, when also the PCH SLOT2 PCI-E 3.0 X4 is in use, then the GPU always went in state 43 and windows crashed.
Now i removed the Intel Quad Port network interface from the Slot2 and it works again.
So looks like, that you only can use PCH Slot 6 and PCH Slot 4, but NOT also PCH Slot 2.
Another GUESS: nvme M.2 #1 in use could result in the same problem, because it is shared with the PCH Slot 2 (If an M.2 #1 is installed, PCH Slot 2 is deactivated anyway). Maybe not sufficient lanes free or whatever? But now i removed the network interface and it works again. IPMI and the GPU for hardware acceleration.