Attempt to create wrapper for CUDA Driver API

Accelerated Computing CUDA CUDA Programming and Performance
1

Hello! In my C# project I’m trying to write wrapper for Driver API

using System;
using System.Runtime.InteropServices;

namespace test
{
    public class DriverAPI
    {
        [DllImport(@"F:\deploy\nvcuda64.dll")]
        private static extern int cuInit(uint flag);

        public static void CuInit(uint flag)
        {
            int err = cuInit(flag);
            if (err != 0)
                Console.WriteLine(err);
        }

        static void Main()
        {
            CuInit(0);
        }
    }
}

but after running this code, I’m getting error 100:
/**
* This indicates that no CUDA-capable devices were detected by the installed
* CUDA driver.
*/
CUDA_ERROR_NO_DEVICE = 100

I don’t understand why, because I have 2 CUDA-capable devices on my computer with Windows 10

2

What happens if you run the cuda deviceQuery sample app? Does it show both GPUs?

3

yes, all other programs/tools indicates, that I have 2 GPUs

4

problem was solved by replacing DLLImport to [DllImport(@“nvcuda.dll”)], but I still not understand, why my 64bit application does not interact with “nvcuda64.dll” properly…