I have to agree with what is said. The developer is also the one who introduced a game called NFS Shift 1 and Shift 2. They were indeed good racing simacades but, back then, ATI support was atrocious. Here is what ATI said officiall about it: https://www.hardocp.com/article/2009/09/22/amds_ati_radeon_hd_5870_video_card_review/10 As was stated earlier the relationship between both organizations wasn't all that great IMO. ATI, rightly, called them out via media. Which started the ball rolling into releasing a patch with an whopping 26% improvement in ati cards. http://www.legitreviews.com/new-need-for-speed-shift-patch-boosts-amd-gpu-performance_1130/3 But that alone didn't really get pCars performing well with AMD cards. Little did anyone know at the time win10 would come to the rescue: https://www.reddit.com/r/pcgaming/comments/366iqs/nvidia_gameworks_project_cars_and_why_we_should/ The performance from Pcars 1/2 came from win10 of all things. Something AMD was able to do in win10 that they weren't able to do in win7/8.1. That plays a big role as to why pCars run decently with AMD cards to this very day. Nice performance bump for AMD cards with win10. For those who were into pCars had to upgrade to win10 to get that performance increase. Which, IMO, started the rumor that win10 was faster then win7/8.1. From the developer of pCars: ... https://hardforum.com/threads/proje...ormance-issues.1861353/page-2#post-1041593386 But AMD cards are still slower then its competing card. As pCars 1/2 still uses physx. Yes, physx: https://www.pcgamer.com/project-car...entionally-crippled-performance-on-amd-cards/ IMO, the issue with ACC reminds me of this all over again. I too had a thread on the subject here: https://forums.guru3d.com/threads/r...upport-for-assetto-corsa-competizione.421418/ Here is a thread that thoroughly discuss the performance between AMD/Nvidia. Even stating that AMD hasn't even provided support. Which is similar to me asking them about support and not getting an answer. https://www.assettocorsa.net/forum/...-going-to-run-worse-on-amd-cards.50450/page-4 This really sheds some light on the situation. Edit: Sorry for the long read. But I wanted to provide some pointers to history about the info via links about the drivers of ATI/AMD and games that are involved with TWIMTBP program.