I want to use a 3D-grid for calculations with cuda. This page [1] or this answer [2] says I can use three dimensions for this, but querying my device properties gives me the following:
--- General Information for device 0 ---
Name: Quadro 4000
Compute capability: 2.0
Clock rate: 950000
Device copy overlap: Enabled
Kernel execution timeout : Enabled
--- Memory Information for device 0 ---
Total global mem: 2146631680
Total constant Mem: 65536
Max mem pitch: 2147483647
Texture Alignment: 512
--- MP Information for device 0 ---
Multiprocessor count: 8
Shared mem per mp: 49152
Registers per mp: 32768
Threads in warp: 32
Max threads per block: 1024
Max thread dimensions: (1024, 1024, 64)
Max grid dimensions: (65535, 65535, 1)
If I try to use a 3D grid with my code nothing happens:
__global__ void updateBuffer( ... )
{
int x = blockIdx.x;
int y = blockIdx.y;
int z = threadIdx.x;
int offset =
x +
y * width +
z * width * height;
buffer[offset] = ...;
}
__global__ void updateBuffer2( ... )
{
int x = blockIdx.x;
int y = blockIdx.y;
int z = blockIdx.z;
int offset =
x +
y * width +
z * width * height;
buffer[offset] = ...;
}
void callKerner() {
dim3 blocks(extW,extH,1);
dim3 threads(extD,1,1);
dim3 blocks2(开发者_如何转开发extW,extH,extD);
dim3 threads2(1,1,1);
updateBuffer<<<blocks,threads>>>( ... ); // works fine
updateBuffer2<<<blocks2,threads2>>>( ... ); // nothing happens
}
So is it that 3d grid do not work with some cards?
[1] http://en.wikipedia.org/wiki/CUDA#Version_features_and_specifications [2] Maximum blocks per grid:CUDA
i fixed it by installing the latest nvidia driver and updating to cuda 4.0
There's a clue in this line:
Max grid dimensions: (65535, 65535, 1)
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