HOw to interpret the c1/c2 tests

It seems most people on this don’t care much about cd-r’s anymore but I still burn alot. WHat are the acceptable limits for these? I tried doing a search through the forum but i found nothing.

Good question.

I’ve had scans that looked terrible, but were readable (see first attachment). that was burned on cheap media with a very old 4x CD writer.

The second was burned on better media with a Plextor PX712a, and that result is fairly typical.

At a guess, I’d say C1 errors don’t matter too much, but any C2’s will cause the drive to slow down and re-read the sector a few times. Any CU’s mean that sector is largely unreadable. Also, there seems to be a lot of C2 errors in the vicinity of a CU.

there’s a sticky in the Media forum (in CD-R/RW Media Tests section) entitled “Interpreting C1/C2 Scans”…answers to your question can be found there.


To summarize rdgrimes’ long post that drpino was referring to:

Under 20 C1 max +
Under 2 C1 average +
NO C2 errors

= excellent.

Anything outside those ranges is not excellent, but might well be perfectly readable/playable anyways.

And I’ll add a Plextor twist from personal experience:

A single CU error (or more) is/will be soon a coaster.

I Dont have the graph but on a cd i burned on my laptop a while ago, I ran the test and i had c2 errors everywhere. AT one point there was a solid bar of c2’s shooting through the roof. But the cd plays just fine…