How do I test my NEC drive?

I have two NEC DVD±RW NE-3450A drives. I suspect they are getting worn out (or just getting dirty?) since recently they started producing more and more coasters, on different brands of media. Before I invest on more expensive media or get a new burner, how can I test the drives? I read a lot of threads here, especially the test with Nero CD-DVD Speed. But I still have at least two basic questions.

  1. What kind of media should I use to perform the test? It seems without inserting a CD/DVD (either blank or with data), I cannot do a test.

  2. How can I tell if the drive is bad (or less functional) once the result is out? compared to what standard? say, the test reports an averaged writing speed of 3.8X, … it seems slow, but how do I know it is because of the media or the burner?

Many thanks!

There is an article here which may be of some interest to you.
http://www.cdfreaks.com/reviews/Home-PI_PIF-scanning---Who-to-believe/

Thanks for the link! I will take a look.