using flac -8 figure 50% of 700mb so 350 mb but how many cd,s are the full 700mb.. so to flac 2000 cds what kinda of space should I figure?

80 min. CDDA = 700 Mbytes of space. If the CD has, let's say 50 min. It will take a lot less space, specially after encoded in FLAC files.

safe?
350 x 2000

C.

<edit>removed unnecessary sarcasm</edit>

In my experience the average compression ratio is closer to 55%, but you might want to calculate using 65% or 70% to err on the side of caution.

have a look here, for a rough idea of compression.

http://www.hydrogenaudio.org/forums/index....showtopic=61054

Don't forget that a 74 minute CD contains nearly 750 megabytes of audio data.

The average length of a CD depends a lot on the genre. In my experience classical CDs are usually nearly filled and rock CDs are closer to half full.

so maybe 70% of 700 = 490 *2000=980000 so a terabyte should do?

Maybe, but would you not want to have a backup - to avoid all of the labour involved in re-ripping the CD's IF the first storage medium failed?

It's a classic case of time=money. In this case I would spend the money to get 4 x 500GB HDD's and have two independent copies - one online and one near-line. If the extra 2 x 500GB HDD's cost approx $250, at 10 minutes per CD (plus tagging correction if necessary) for 2000 CD's, then that's a effective per-hour cost of $0.33 to not have to rip all the CD's again.

[edit] 2 x 500GB HDD's do not cost $500, amended to $250.... [/edit]

Have a look here: http://www.olive.us/products/storagecalculator.html

1 Tb should do, 750 is a bit critical

Interesting as according to that site 1tb will hold 2900 discs which is 900 more than I am calcualting

FLAC compression is depended on the complexity of the signal.
CDs varies in length
Any calculation has to made some assumptions so results might differ.