OpenACC was initiated by NVidia when OpenMP did progress too slow for supporting accelerators with directives.
OpenACC is made for accelerators, where later on CPUs have been added. This gives the biggest difference with OpenMP, which was made with CPUs in mind and where accelerators have been added.
- CPUs. X86 and ARM
- NVidia accelerators. Tesla, Tegra, GeForce
- AMD accelerators.