來自官方的說法： SOLUTION: you need to reinstall PhysX drivers. Uninstall current one, than install PhysX_10.05.12_9.10.0512_SystemSoftware package manually, from \Steam\steamapps\common\mafia ii – public demo\3rd 1. run GPU-Z, no Physx 2. go to(c:\Program Files (x86)\Steam\SteamApps\common\mafia ii – public demo\3rd\) 3. run PhysX_10.05.12_9.10.0512_SystemSoftware.msi, uninstall physx 4.run again PhysX_10.05.12_9.10.0512_SystemSoftware.msi install physx 5. run GPU-Z, Physx oh YES 6. run Mafia 2 我的還沒下玩，有安裝過的可以試一下。