y

x

z

blockDim.x

blockDim.y

blockDim.z

(0,0,0)

(1,0,0)

(0,0,1)

(0,1,0)

(1,1,0)

(1,1,1)

(1,0,1)

(blockIdx.x, blockIdx.y, blockIdx.z)Tuple specifies the coordinate of block

*Idx.x, *Idx.y, *Idx.z are CUDA managed variables* = thread / blockblockDim.* and gridDim.* are initialized by CUDA

Programmer has to specify DimGrid(gridDim.x, gridDim.y, gridDim.z)and DimBlock(blockDim.x, blockDim.y, blockDim,z) as kernel launching parameter