Nero cd speed scandisc function: what is ok, whats not?

vbimport

#1

im collecting mp3s now for awhile allready and i now have ALOT of them on cds

because in this last years i used also ALOT of different brands of cds, i decided to test what cds where still ok and which ones should be backupped...

thats why i used nero's cd speed scandisc function to test them

now i know that a few damaged sectors aint bad as long as it aint to much of them (or as long as theyre not bad)

but the problem is:
WHAT IS TOO MUCH?

im now testing my mp3 cds (beginning with the oldest)

mmore gave 0.12% damaged sectors (the file test was no problem) and its read at 15x avarage
the basf gave 3.45% damaged (file test was ok too --> but for how long will that last? is this still trustable?) and its read at 15x avarage
the first nashua gave 0.11% and its read at 15x avarage
strange: the second nashua i test tests about 1/3 slower then the previous (10x) BUT has 0% damaged sectors? i dont really get that... can anyone explain? (is the speed that the cd is read also a factor to the quality of the media?)
the 3th nashua 0.46% and its read at 12x avarage
then comes an unknown cd (printed cd) which gets 4.76%damaged sectors and its read at 5x avarage
then a basf which has a few damages (little) which has 5.13% damaged sectors and 0.80% unreadable sectors and its read at 3x avarage

btw: im reading them in my old aopen 20x4x4x writer (so my cdrom and new liteon dont wear of :p) so 15x is ok

im makin a table of it

ill post that one when its done (it might be usefull in choosing a brand)

so can anyone tell me from how much % i should think of backupping them?

btw:
a little second question --> does it matter what drive i use to test this? (as long as it supports error detection)

loool

i allready know my little question...

i just read that cd with unreadable sectors in my liteon 40x24x10x and the result is 0.11% damaged sectors, 0%unreadable :), and at 28x :smiley: (ill still copy this cd though :p)

but ill keep on using my old aopen cause that gives me a better view of what is wearing of (perhaps ill do the recent cds in both to get an idea about media support (my liteone didnt read all cds i put in him, and sometimes my cdrom does read them)


#2

blah

(pressin quote instead of edit sucks)


#3

euhm

did no one on this whole fucking forum EVER wondered if his cds are still intact???

cause if no one even knows how to interpret the results then no one can really use it either eh…

this really disappoints me…
:frowning:


#4

damaged , i believe, means that there is something wrong in the 2048 bytes, and was recoverable based on the 304 of error correction. un-readable probably means both are beyond repair. there isnt really a ‘too much’. oftentimes, as you found, changing the reader changes what is read. also, occasionally, opening the cdrom, and moving the cd ever so slightly can change what is readable, and what isnt. kinda weird.


#5

nobody has actually answered his question. what is acceptable in damaged sectors?, 1% or 2%…


#6

100 % is acceptable. damaged doesnt really mean anything special. unreadable, on the other hand, = bad :wink:


#7

unreadable, on the other hand, = bad

thats not totally true. if u scan an original, a sd2.5 disk will have unreadable sectors at the beginning and the rest readable (no damaged though). this could be the protection. then when u scan the copied disk it should look the same with the unreadable sectors in the same place. there should be no damaged sectors if its a 1:1 disk but can someone (admin?) tell us how many damaged sectors are acceptable. i did a mohaa disk but it doesn’t work and that has 20.45% damaged sectors, so can we use this as a starting point?

anythoughts would be much appreciated


#8

yes, a safedisc disc will have unreadable sectors. but an mp3 cd, which you were talking about originally, should not have protection, should it? keep your focus :wink:


#9

keep your focus

sorry boss, :stuck_out_tongue: if thats the case, the scan should only show green sectors if its pure.


#10

yaya, the problem here is that the question is very arbitrary :wink: ‘too much’ is a personal thing…having a damaged sector is expected! i cant remember the ratio’s, but the drive, on the box, should actually tell you how many bits out of how many it will write incorrectly. in conclusion, i really dont know :slight_smile:


#11

well, the method that I use and it seems to be the same that OCFreak uses for his burns is:

95% or better good sectors, no unreadable sectors = the disk is acceptable

Less than 95% good sectors or any unreadable sectors means the disk is not readable overall.

So, in general 5% or higher damaged sectors will have an effect on the disk’s playability. Also, believe it or not, the numbers of damaged sectors may vary from reader to reader, complicating matters.

Others may use different standards.


#12

ive tested allmost all cds now

and ill post a big list with lots of stuff to study about this matter :slight_smile:

and on first sight it seems like the program aint able to tell if a cd is still good or not…

but im in exams atm, so it can take awhile before i finish it