Found this fix for the game on reddit which seems to fix the terrible stutter problems that people are having;

https://www.reddit.com/r/NoMansSkyTheGame/comments/4xgw82/pc_users_incredible_fps_fix/

The Fix:
Is to create a shortcut to the games executable file “NMS.exe”.  Then in the target window paste the following;

C:\Windows\System32\cmd.exe /c start “Process Monitor” /High “E:\GOG Games\No Man’s Sky\Binaries\NMS.exe”

Note:
Replace “E:\GOG Games\No Man’s Sky\Binaries\NMS.exe”with the path to game on your system.

EDIT:
This fix doesn’t work for me and in fact seems to make the game perform even worse, its best to update to the “BETA / Experimental” Patches available on Steam and GOG.