OpenACC grid size

Accelerated Computing HPC Compilers Legacy PGI Compilers
1

Hello!
Is it possible to create 3d grid in OpenACC, for example: grid [1616512] block [16*16]?
When I try to add gang directives to 3 nested loops, pgcc just ignores 1-st level loop and creates two-dimensional grid.

2

Hi Alex,

Is it possible to create 3d grid in OpenACC

While NVIDIA did add a third dimension to their grid launch specification, the third dimension is actually run sequentially from the host. Hence, we kept using just the two dimensions that run on the GPU. We may change this in the future if there is a performance relevant reason to do it, but for now now, no you can’t create a 3D grid.

  • Mat