I know when it stops writing that when its dead but I’m talking about before that. could it possibly decline in read and write speed at a certain speed you select specifically. Like when you choose to write a disc at 16X but it drags down to 12 or 8X or is does the whole drive fail and not slowly degrade with time. Post some your ideas … Also is there a dianosis program for testing a CD-DVD RW drive.
If your drive writes @8X and 12X speed without any lots of error then the drive is OK but if %30-%50 of it is not error free then it is the time to consider replacing it fwith the new one.
Keep in mind that burning speed derives from several variables, not just due to drive conditions (drive, software, media, PC load - including CPU, memory and bus).
Drives are “prepared” to have a working life measured in average terms and referred to hours of active use and hours of activity (“on” status), and failures can come from mechanical or electronic reasons.
Software conflicts and dusty lasers can degrade performance with no relation to an “expected” upcoming dead.
Not an easy diagnostic, because you can have an heavy worker drive still in good shape or one that can die on you with no warning signals.