I Downloaded it myself and have about 5-10fps in the main menu on a RTX3090 64GB , 3950X. Most of the reviews say the same. Colossal Order are suggesting you should play on very low detail. I was a massive fan of the original having played Sim City since 1993 but I cant even get into this. It shouldnt have been released so early IMO
I've been playing on the Gamepass version (which was gifted to me by a friend). It's not spectacular performance on my 8th gen i7 and 6700K...but it's playable. I'm enjoying myself. I'm averaging around 25fps in game. Only setting I really modified is the Volumetric setting...set that to low. Playing at 1440p.