I have been dealing with severe FPS drops that have gotten even worse after the latest update.
GTX1070 ROG STRIX, 16GB RAM@3000Mhz, i5 9600k, game installed on my main M.2 970 Evo using a 1440p 144Hz monitor (as if it would ever reach that...).
In chill areas during looting mode I get 90-120FPS, but in big open areas, where there's grass or lots of visual effects like smoke, bullets, airstrikes, aiming down sights etc. it can go down to 40-50FPS, which is such a harsh drop that I often lose a fight just because of the performance issues, as you can understand it's super frustrating. I already tried every troubleshooting step imaginable but given the number of players that have this issue I can see it's not on my end for sure.
I am 100% certain it's an optimization issue because even lowering the resolution doesn't fix the problem, yes I get more FPS but in those specific situations I still get drops below 60.
The only thing that helps is disabling AA, that actually gives me enough FPS to push through the drops but the game looks absolutely terrible. I enabled FXAA 2x from the Nvidia control panel to make it somewhat bearable. It's not much of a solution though, considering how the game looks with the lowered settings it should NOT run this badly. I can't believe a simple smoke or explosion/waterfall effect causes a 60+ FPS hit, come on.
Also, sometimes the game doesn't feel smooth even when running at high frames, with Vsync off. I've seen a lot of users report this too.