Hi,
I am using a PC with three RTX A4000 cards, one in WDDM mode for displaying, two in TCC mode for calculation.
Driver version is 551.23. OS version is Windows 10 21H2 (build 19044.3570)
After switching 2 cards into TCC mode, I cannot see the Nvidia Control Panel any longer by right-clicking on the desktop. I also cannot get GPU information (e.g. by calling NvAPI_GPU_GetFullName) with a small command line application using NVAPI R367.
nvidia-smi output looks good:
±----------------------------------------------------------------------------------------+
| NVIDIA-SMI 551.23 Driver Version: 551.23 CUDA Version: 12.4 |
|-----------------------------------------±-----------------------±---------------------+
| GPU Name TCC/WDDM | Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|=========================================+========================+======================|
| 0 NVIDIA RTX A4000 TCC | 00000000:16:00.0 Off | Off |
| 41% 34C P8 6W / 140W | 8MiB / 16376MiB | 0% Default |
| | | N/A |
±----------------------------------------±-----------------------±---------------------+
| 1 NVIDIA RTX A4000 WDDM | 00000000:AC:00.0 On | Off |
| 41% 54C P0 43W / 140W | 233MiB / 16376MiB | 0% Default |
| | | N/A |
±----------------------------------------±-----------------------±---------------------+
| 2 NVIDIA RTX A4000 TCC | 00000000:CA:00.0 Off | Off |
| 41% 34C P8 6W / 140W | 8MiB / 16376MiB | 0% Default |
| | | N/A |
±----------------------------------------±-----------------------±---------------------+
ControlPanel is missing:

The problems are gone when I switch back to WDDM mode. Only one card in TCC mode is also working fine.
Driver version 472.47 does not show these problems.
Thanks for help.
Regards,
Jan