Which API call returns the nvidia ROP count?

[zebulon]

Hi there,
We are a bunch of Linux users/developers and would like to be able to check the ROP number from our nvidia Blackwell cards, following the missing ROP debacle. Problem is, nvidia-smi, which exists in Linux, does not seem to return this info. The proprietary driver on Linux is aligned with the Windows one, so we highly suspect this is possible. Would you be willing to share which API call is made to retrieve this information? Many thanks in advance.

 

[W1zzard]

If it's not listed in the public docs it's under NDA. Only way is to reach out to NVIDIA for NDA access to NVAPI

 

[zebulon]

Thanks a lot W1zzard, we suspected something like this. So I suppose that for GPU-Z you are under NDA, is that correct?

Edit: I already looked into the NVAPI documentation. Does not seem to see it, but it is not easy to search. Especialy ROP can be referred as "Raster Operation Pipelines" but also sometimes "Render Unit".

A CUDA developer suggests as well to check whether Nsight Graphics lists those stats in the app profiler.

 

[zebulon]

OK, we could determine that there is a pivate function call to get ROPCount (called NvAPI_GPU_GetROPCount) from a physical GPU handle, in the NVAPI. There is a very nice falahati/NvAPIWrapper: NvAPIWrapper is a .Net wrapper for NVIDIA public API, capable of managing all aspects of a display setup using NVIDIA GPUs project that contains a list of all these functions. Unfortunately, it seems its implementation may be missing in Linux, but we are still searching and querying nvidia on their Linux forum.

 

[W1zzard]

So I suppose that for GPU-Z you are under NDA, is that correct?

Correct

 

[zebulon]

Correct

However if I understand correctly the Github wrapper project, NvAPI_GPU_GetROPCount() may be listed as part of the “Private Internal NvAPI Functions”, but it is not a "secret" under NDA, correct?

 

[W1zzard]

but it is not a "secret" under NDA, correct?

I can't comment. I have an NDA with NVIDIA, they provided information to me under this NDA, and I will follow those rules. I'm not a person to dance around words and try to find loopholes

 

[zebulon]

I understand. It is just that the function is listed in a public Github repository and the author does not seem to have an NDA (from reading his posts). In addition, the function can be found in the headers. The only issue here is if the same function is not available under Linux API.
By the way, in the NVAPI Wine Github project, the same Id is used for a function with another name: {0xfdc129fa, NvAPI_GPU_GetRasterBackendCount}. Wine being a Linux project, this gives some hope.

 

[zebulon]

Great news! The solution has been found by Miro256 on nvidia Linux forums: https://forums.developer.nvidia.com...er-linux-affects-all-rtx-50xx-cards/324769/58
The function API was found not in nvapi but in the open source drivers (hence solution is 100% legal and does not require an NDA), and Miro256 has posted C code that returns ROP counts.