I'm having the same issue, Game normally plays fine 1440p 140ish fps but have been dropping down to 20-50 this morning. It is pretty unplayable right now. Ryzen 3700x Nvidia 2070 Super 16 GB of RAM I've tried changing settings down and it is still happening.

Hey there! Below are suggestions that may help with your issue: [quote][b]1.[/b] [url=https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335]Verify the integrity of your game files[/url] on Steam. [b]2.[/b] [url=https://www.bungie.net/en/Help/Article/46407]Remove your CVARS.xml[/url] file. [b]3.[/b] Try lowering your graphics settings, capping your FPS, lowering your FOV, and changing your Window Mode to Windowed. [b]4.[/b] Turn VSYNC on and/or off. [b]5.[/b] Lower the clockspeed of your GPU. [b]6.[/b] Lower your hz on your monitor. [b]7.[/b] [url=https://www.bungie.net/en/Forums/Post/250853399]Remove the Windows Gamebar[/url]. [b]8.[/b] [url=https://www.bungie.net/en/Forums/Post/251664497]Edit your Radeon Gaming Settings and Shader Cache[/url] if you use a AMD Radeon card or Reset/Optimize your game's graphic settings if you use NVIDIA GeForce Experience [b]9.[/b] Check your CPU cooler/fan to see if it's having issues or needs an update. [b]10.[/b] [url=https://www.bungie.net/en/Forums/Post/255227975]Manually specify that Destiny 2 should use your GPU in your PC Graphic Settings[/url]. [b]11.[/b] [url=https://www.reddit.com/r/DestinyTheGame/comments/d1cnx4/fixed_weird_lagpoor_fps_on_pc_no_matter_how_low/]Go into Windows Audio Settings and change it to 16 bit, 44100 Hz (CD Quality)[/url]. [b]12.[/b] Use your laptop’s power cable. [b]13.[/b] Sign out of Friends on Steam[/quote]

Let me guess, laptop? (Odd Ram size by the way).