Interesting. I hadn't heard of disabling HPET before. I gave it a shot in one match and (after a reboot) didn't immediately notice a difference, but I'll keep an eye on it. It might help OP though so, thanks for the tip!
I still think OP's issue is that they're pushing literally double the pixels you are with a slightly worse CPU and slightly better GPU. (Although, he likely also has less VRAM than you, which would hurt, too.) It's likely just too many pixels with not enough power. You'd need some decent horsepower to get smooth framerates even on all-low settings with a massive screen like that. I'm honestly surprised and impressed they say their fps is stable outside of high-activity areas.
After a lot of tweaking, with literally every graphics setting on low and DLSS on performance, I can leave the render resolution at 100% at 3440x1440 and get 60-70 fps in-game (105-130 fps in menus and 145 in the shooting range, weirdly), on a 5800X and 3070Ti.
I'll stop harping on the resolution though, just in case there really is some other possible issue. I would love to be able to scoot my settings even up to medium.
Did you activate rezisable bar in bios + with Nvidia profile inspector for battlefield 6? Huge gains if not done already
