NvAPI_GPU_GetAllDisplayIds counts 9 outputs on a Quadro RTX 5000


I’m using NVAPI (R525) to get info about my system topology, as the “View system topology” page in the NVIDIA Control Panel does.

I currently have a Quadro RTX 5000 which has 3 DisplayPort and 1 USB-C connectors. I’m trying to get all the possible outputs through calls of NvAPI_GPU_GetAllDisplayIds, as explained in the doc, but NVAPI seems to count 9 DisplayPort and 0 USB-C outputs.

None of these outputs are considered “Dynamic” nor “MultiStreamRootNode” by the API (see NV_GPU_DISPLAYIDS). Also note that display ids seem valid and connected displays are correctly listed.

Why is the NVAPI outputs count different from the number of physical connectors and how to retrieve the physical information?

Thanks for your answers,

Dear @guillaume.b

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Our technical team has received your query. We will get back to you after initial investigation.

NVAPI Forum Moderator

Dear @guillaume.b

Thank you for contacting NVIDIA Developer Forum.

For each DP connector on the graphics board, there are two displayIds enumerated by NvAPI_GPU_GetAllDisplayIds. The first displayId represents the main standard DisplayPort output. The second displayId is there to accommodate the DP/HDMI dual-mode support where an HDMI monitor can be directly connected to the DP port through a passive DP to HDMI converter. Depending on whether you use a DisplayPort monitor or an HDMI monitor with a passive DP to HDMI converter, you should use the first or second displayId for your output. For each USB-C port, NvAPI_GPU_GetAllDisplayIds enumerates one displayId.

We hope this resolves your query.

NVAPI Forum Moderator

How do other NVAPI display functions like NvAPI_GetHDMISupportInfo and NvAPI_GetDisplayPortInfo react to converters?