I don't know if it's a coincidence but those 2 Chinese tracks have the worst performance hit on fps. I could race with a grid of 36 cars on pretty much all other tracks with 1440P 4xAA and all the graphic settings on High with a locked 60fps. However with the mentioned tracks, I could barely race with a grid of 12 cars with 40-55 fps, anything more than 12 cars the race will turn into a slide show. There are a couple of places on each track that are particularly bad. On Shanghai it's at T1 and T2 and the S before the back straight with spectator seats. On Zhejiang it's when you see the hill up close around T5 (I think). Driving alone on the tracks poses no prob or with a grid of less than 6 cars. Once past 12, the fps starts dropping to an unbearable level. BTW I can play Project Cars 2 or Dirt Rally 2.0 at 1440P with a mix of ultra/high settings at locked 60 fps 90% of the time with occasional dropping to 55-ish when things get "dense". So I believe those 2 tracks are in desperate need of some serious graphical optimization. It's a shame that I really like those 2 Chinese tracks especially Shanghai. I hope the devs will do something with them in later uptakes. Thx!