A warp, or wavefront in AMD GPU, or subgroup in Vulkan, OpenCL, and OpenGL.

All threads in a warp execute the same instructions. If threads in a warp have diverge branches, the scheduler will run both branches on all threads.

warp_diverge.png

In CUDA

On CUDA, all threads in warp is executed on the same streaming multiprocessor. Threads in a warp has consecutive threadIdx values.

See Also