MGSV:GZ is a greatly optimized game, but with so many random PC configurations out there, like every other game it comes with a few flaws too. These include occasional lagging and freezing. Thankfully I was able to fix them.
Although, a little out of the ordinary,it can be done by opening up the task manager while running the game –
>>Details Tab >> right click MgsGroundZeroes.exe (both)>> real time priority.
Note that this has to be done every time you start the game. and to both tasks called MgsGroundZeroes.exe.
Hope that this will improve your game’s performance.