SSIA

When using EAC,

Is it better to have Track Quality at 100% or watching CRC's (t+c mode)?

Thanks, in advance for any and all views and insights.

CRC.
If any single bit changes, CRC value won't be the same.

Yes, but what if the drive reads a corrupt region twice and returns the same CRC value each time? In that case CRCs won't do you any good.

Track Quality at 100% means you have a 100% correct rip. There are no exceptions. But even if the quality is at 99.8 or 99.9% chances are that you have a perfect copy. It is practically guaranteed you won't hear any differences. I would only start worrying once it drops below 98%.

Also, remember to keep all C2 error correction options OFF. C2 may be very fast, but you pay for it with the off chance that the C2 will miss some errors, which it can and will. The only way to get the best rip possible is with all hardware error correction turned off and let EAC handle it by rereading each sector.

thanks....

I knew about the c2 stuff, but I was unsure which was better to check. Ideally they both hit

According to all I've read, and granted that the right secure mode is used, I think 100% quality is a bit more secure than CRC OK.

CRC OK can fail if the same error occurs twice. There must be very few errors for this. Case reported at least once.

100% quality can fail if the drive caches and cache is turned off. I don't remember someone ever reporting CRC mistmatch for 100% quality rips, but few people take 100% quality as a hint of secureness yet.
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Links, in no special order yet :

How to accurately detect C2, accurate stream, overread, etc
http://www.digital-inn.de/showthread.php?threadid=9805 @EAC

Safety of C2, of caching, and of reading twice
http://www.digital-inn.de/showthread.php?t...?threadid=14600 @EAC

Drives with perfect C2
http://www.digital-inn.de/showthread.php?t...15&pagenumber=4 @EAC, 6th post in this page, by Registered

[EAC beaten??] CD-Freaks - Review - Plextor's PlexTools @EAC

Error correction and interpolation in CD ROM drives : Discussion reliability DAEquality test @EAC

Is accurate C2 error reporting an Utopia? @EAC

Explanation of C2 support : Drive options => 'capable C2 info' vs 'use C2 info' @EAC

Matching CRC for errored rips @EAC

I thought that was what we were supposed to do...

thanks for all of the reading material- -that's why you are the uber-moderator...

Correct me if I am wrong...EAC has 2 was of telling a track has errors:

1. CRC checking 2nd sector rip
2. C2

But if you have C2 switched off, how will Track Quality give you a correct value, where CRC would not?...

Could you restate this? I am a little unclear as to what you mean...

Thanks.

Putting it this way, there is no other magical 3rd method of determining if a rip is correct, so if C2 is switched off (quite rightly so it is a minefield on lots of drives), then the rip is relying solely on CRC. I have seen many disks give out a constant CRC, even though they are ripping wrong, EAC works like:

Rip Sectors,
Re-rip Sectors
If same continue

in a simplified way, the 'if same' is going off CRCs, at the end of the rip a wrong CRC would be produced on those bad discs that give out constant errors, and the track would appear to have a 100% rating...

so if not using c2, getting matching crcs is the best way to know the rips are exact, right?

I don't follow you... you seem to talk about CRC for sectors. AFAIK, EAC doesn't compute CRC for sectors, why would it waste the time for ? One sector can easily fit in the RAM of any computer and be directly compared with a reread.

I follow you when you say that 100% quality can come out of a CD with repeatable errors, but where does the "wrong CRC at the end" come from ?

That is what I meant, didn't want to complicate it for non-programmers, of course it can do a ~26 sector compare.



It will give a constant CRC (wrong) which EAC thinks is right, but it is not the CRC of the true unscratched CD.

BTW the time has come to spill the beans on AccurateRip, see here:

http://www.hydrogenaudio.org/forums/index....=ST&f=20&t=4789

hmm, what do you think about my method? Ripping the CD with EAC secure using the C2 informations (which seem to work well) and when its done read test the CD in my other drive in burst mode. That seems to work