Red Faction: Guerrilla
From PCGamingWiki, the wiki about fixing PC games
Red Faction: Guerilla is a PC port of a console game. DirectX 10 mode causes some big performance hits. Template:Infobox Red Faction (series)
Performance Issues
DirectX 10 mode is not optimized, and therefore when enabled can cause large performance drops on high end computers. Simply disabling Ambient Occulsion can enable a 30FPS performance boost.