https://blendermarket.com/products/uvpackmaster

 

UVPackmaster is the most efficient UV packer out there in terms of packing on CPU, but it also provides a Cuda-accelerated variant of the algorithm. When running on a GPU, it significantly outperforms all other packers available.  But what can be faster than running an algorithm on a GPU? Running it on the CPU and all GPUs in the system simultaneously! UVPackmaster will do exactly that to reduce the time needed to perform even the most advanced packing scenarios to seconds.