How important is an "excellent" PI/PO error scan?

Some say an excellent scan if you get below 20 all the way (or below 10??).

Assuming we keep the disk in a proper storage, does it mean a disk with an excellent scan can “live” 100 years or more while only a good scan (below 280) will “live” less?

Or probably the question is “how bad is a disk with a PI/PO error of 100 to 280 all the way?”

Are there any technical arguments?

sorry if this has been covered before.

I may be wrong, but one idea may simply be that if a disc writes/reads with very low errors the implication is that it is well-constructed, and thus should be able to last longer.

Then again, I’ve had lots of CMC CD-Rs that wrote fine the first time around and died several years later, but I never checked the errors on them the first time around, C1/C2 checking being nonexistant back then :slight_smile:


good questions. The truth is that nobody knows for sure.

CISD/NIST have performed some initial accelerated aging studies with dvd-r media.

They concluded that PIE of 280/8ECC floating window in reading a disc was a relatively good max level under which media tended to have safe margin for longer storage.

However, it is possible to lose even ‘good burns’ that are just made onto really poorly bonded media or otherwise unstable media. The chemical stability of the disc is what really matters in long term storage. That stability is determined by chemical / disc quality and storage conditions (radiation, gases, acidity, solvents, humidity, temp).

So, your best bet is to use high quality media (say metal azo, which MCC claims over 100 years of storage in stable archival conditions) AND make sure the burns read ok.


PS Let us not foget, that the errors are in the reading, not on the disc. Discs don’t have 100-280 PI errors, it’s the drive that reads the disc that sees those errors (due to lower level errors on the disc).