For those of you currently running a single stick of RAM, or don't have it setup in Dual channel mode, this made a huge difference for me:
My original system:
i5-9600k
16GB (1x16GB 3000MHz XMP)
RTX2080
NVMe SSD
Bought game at launch and the performance has been terrible. FPS dips down to 30s, maxing at around 100, average of around 50 with lots and lots of jitter. Tried loads of things; configs, console tweaks, display tweaks, image scaling, reinstalling on different medium (HDD, SATA SSD etc), reinstalling Windows... A LOT. Nothing really helped.
Realising how CPU heavy the game was, I wondered if having memory running Dual Channel would make a difference, so bought a matching 16GB module to go with what I had (Corsair Vengeance 3000MHZ XMP). Installed it, set it back up to run XMP, disabled the paging file (thought I might as well with 32GB RAM) and loaded the game.
Wow, what a difference. FPS rarely drops below 70, averaging at a round 90. No more jitter, a complete night and day difference. I also gained another maybe +10 fps using Shady NZ's config files, which he has kindly shared: here. If you try these, you'll most likely have to setup some of your key bindings and sensitivity options again, but could be worth it for you.
I hope this helps some of you - good luck 🙂