Something is wrong there.. Although it's hard to say what. But as an example.. my 8 X burner will pop out an audio CD of around 70 minutes length or so, in about 9 minutes. Naturally, If this were capable of 16X burning speed, then the same CD should be completed in just over 4 minutes..
All I can recomend is that you double check all your settings, Like burn speed, cache setting blah blah etc etc..