PSA if getting REALLY low FPS/stuttering on high end gear

I wasted SO much time chasing my tail trying to figure out what the problem was running AMS2 and hoping I can maybe save someone some heartache down the road should they end up in the same situation. It started out of the blue and made no sense...

I'm an old school AMS2 guy. Don't post, but been around from the early days. Few days ago I load the sim and it's utterly unplayable. Menu lag, FPS in the single digits, takes forever to load, etc. For reference, running 4090, 9950X3D, everything on liquid cooling with stable overclocks. Even with triple 4K, she rips...usually. LMU and other games were still working as they should so it definitely seemed to be specific to AMS.

Started checking for game updates. Then checked for mod updates (have a million mods installed). Still no luck, so figured a mod may be causing the issue, but before going nuclear and removing all mods, did a steam verification of game files. Still no dice. Realized there was an update to ReShade so I crossed my fingers and prayed that was the culprit/fix. Ugh...no dice. Go full nuke and remove all mods, set everything back to factory clock speeds, default graphics settings, vanilla base everything on a fresh new install. Should work now right, RIGHT?! Nope!

TLR It ended up being that the game was running on the lil GPU off the CPU. No idea how or why it ended up defaulting to that, but the clue was both CPU and GPU (for the 4090) were single digit utilization when the game was chugging along at 9fps. Task manager then showed the AMD GPU maxed out. Frustratingly, I checked task manager early on but missed that part.

The fix is to search "graphics settings" and scroll down on the apps section until you find AMS2. Hit the down arrow within AMS2 and manually select your high speed GPU from the drop down in GPU Preference. Tada! No idea how or why it changed to that, but back to working as it should. Good times...