Windows 10 64 bit
Intel i7 6700K
Nvidia GeForce 1070
CPU 128 x 128 : 3m 51s 75’‘
CPU 64 x 64 : 3m 40s 31’'
CPU 16 x 16 : 3m 35s 19’’ This is the best time from the CPU
GPU 64 x 64 : 2m 44s 31’‘
GPU 256 x 256 : 1m 03s 42’‘
GPU 512 x 512 : 1m 00s 99’’ This is the best time from GPU
GPU 960 x 520 : 1m 11s 12’’
Not bad! Though be aware that sometimes when rendering a large scene or an animation at a high resolution like 4k (and without compromising quality by reducing samples or light settings), it will take an hour or two if not more! Though if you have a finished product of that size, there is always the option of sending it to a render company to have them do the render work for a small price.
Thank you for your comments. I am not planning as yet to get into 4K rendering. For the moment I will be sticking to HD 1920x1080. But, I will keep your advice in mind, as one should never say never…