Please see https://docs.nvidia.com/cuda/parallel-thread-execution/index....

The "video instructions" are indeed another exception: Operations on sub-lanes of 32-bit values: 2x16 or 4x8. This is relevant for graphics/video work, where you often have Red, Green, Blue, Alpha channels of 8 bits each. Their use is uncommon (AFAICT) in CUDA compute work.