GPGPU.TotalMemory shows extremely huge value

Question

I have a 4GB and a 12GB gfx card with CUDA. In my application I use CUDAfy.NET and when calling the GPGPU.TotalMemory property it shows an extremely huge value (definitely incorrect). Same with FreeMemory. How to fix this?

Console.WriteLine("GPU total memory: " + gpu.TotalMemory.ToString());
Console.WriteLine("GPU free memory: " + gpu.FreeMemory.ToString());

For the 4GB card, TotalMemory shows 18446744072635809792 bytes, FreeMemory shows 18446744072628600832 bytes.

That looks like some sort of 32 bit integer overflow bug. You probably ought to contact the developers let them know about this. — talonmies, Jul 22 '15 at 08:17
OK, I've used the code from http://stackoverflow.com/questions/341243/how-can-i-find-the-amount-of-video-ram-installed-through-a-wmi-call (but had to use a `ulong` variable instead of `int` obviously) and it shows correct memory size now. But I will still try to use the proper CUDAfy functions. — Val, Jul 22 '15 at 10:12
Cutting the upper half of the 64-bit integer doesn't give the correct value either. C0000000 in decimal is 3GB and the current card has 4GB (which is correctly displayed by the code from http://stackoverflow.com/questions/341243/how-can-i-find-the-amount-of-video-ram-installed-through-a-wmi-call) — Val, Jul 22 '15 at 10:23

score 0 · Accepted Answer · answered Nov 02 '15 at 08:29

As talonmies pointed out, this must be a bug in CUDAfy that causes incorrect memory calculation but I found a different method to get the information. Some example code in CudafyByExample is showing exactly how to do that! So, instead of reading GPGPU class' property gpu.TotalMemory, I have to get a list of objects containing properties for each device by calling the CudafyHost.GetDeviceProperties() function, then each object will contain my desired info for each CUDA graphics card:

public static void PrintGpuProperties() // this was copied from CudafyByExample
{
    int i = 0;

    foreach (GPGPUProperties devicePropsContainer in CudafyHost.GetDeviceProperties(CudafyModes.Target, false))
    {
        Console.WriteLine("   --- General Information for device {0} ---", i);
        Console.WriteLine("Name:  {0}", devicePropsContainer.Name);
        Console.WriteLine("Platform Name:  {0}", devicePropsContainer.PlatformName);
        Console.WriteLine("Device Id:  {0}", devicePropsContainer.DeviceId);
        Console.WriteLine("Compute capability:  {0}.{1}", devicePropsContainer.Capability.Major, devicePropsContainer.Capability.Minor);
        Console.WriteLine("Clock rate: {0}", devicePropsContainer.ClockRate);
        Console.WriteLine("Simulated: {0}", devicePropsContainer.IsSimulated);
        Console.WriteLine();

        Console.WriteLine("   --- Memory Information for device {0} ---", i);
        Console.WriteLine("Total global mem:  {0}", devicePropsContainer.TotalMemory);
        Console.WriteLine("Total constant Mem:  {0}", devicePropsContainer.TotalConstantMemory);
        Console.WriteLine("Max mem pitch:  {0}", devicePropsContainer.MemoryPitch);
        Console.WriteLine("Texture Alignment:  {0}", devicePropsContainer.TextureAlignment);
        Console.WriteLine();

        Console.WriteLine("   --- MP Information for device {0} ---", i);
        Console.WriteLine("Shared mem per mp: {0}", devicePropsContainer.SharedMemoryPerBlock);
        Console.WriteLine("Registers per mp:  {0}", devicePropsContainer.RegistersPerBlock);
        Console.WriteLine("Threads in warp:  {0}", devicePropsContainer.WarpSize);
        Console.WriteLine("Max threads per block:  {0}", devicePropsContainer.MaxThreadsPerBlock);
        Console.WriteLine("Max thread dimensions:  ({0}, {1}, {2})", devicePropsContainer.MaxThreadsSize.x, devicePropsContainer.MaxThreadsSize.y, devicePropsContainer.MaxThreadsSize.z);
        Console.WriteLine("Max grid dimensions:  ({0}, {1}, {2})", devicePropsContainer.MaxGridSize.x, devicePropsContainer.MaxGridSize.y, devicePropsContainer.MaxGridSize.z);

        Console.WriteLine();

        i++;
    }
}

GPGPU.TotalMemory shows extremely huge value

1 Answers1