Game has periodic lag spikes for half a second every second

just like the title says, my game is unplayable, i have a more than capable pc to run it, even the recommended graphic settings are set to high and it does show me a 50-60 fps (from the geforce launcher) menu works fine as well but as soon as i get in a game the lag spikes begin, ive tried a few solutions i found online but nothing worked, please help!