I'm having problems, but I can't nail it down to anything in particular yet... So don't go by my experiences with DX8a... Do install it though, I saw a nice increase in frame rates using DX8a. at least under UT/3DMark2000... Now this is on a KT133a system/1.2G Tbird system, I didn't see much change on my P3-800/BX system.