Specifically, going into 'Power & sleep settings' via the start menu, clicking 'additional power settings' and making sure 'Ultimate Performance' is checked.
For some reason every time I turn off/restart my PC windows resets the power plan to 'power saver' which seems to limit all hardware usage % to levels below what Tarkov needs- so I have to do this each time I want to play the game.
In terms of improvement (Running at 1440p on 144hz monitors), without doing this the game would barely get up to 60fps, but with ultimate performance it's steady at 80-100 on any map.
My hardware:
AMD Radeon RX 6800 XT
AMD Ryzen 5 5600X
32GB RAM @ 2400 MHz
