ok, this may sound stupid, but doesn't your burner software tell you at what speed it can burn a CD? I use NERO and I use a NEC 7800 16x and a Lite-on 24x. Depending on the burner NERO will burn my PNY 16x CDs at 4x (NEC) or 24x Lite-on.
Based on this I think a software that tells you at what max speed a CD can be burnt (theoretically!) is useless. It will depend on your burner and how well it can handle the CDs.