We have the 3570-B12 (20 slots and two drives), 3490-E01, and the default 5GB 
8mm tape drive. I have found that the 3570 is roughly twice as fast as the 3490 
and the 3490 is roughly twice as fast as the 8mm. Not sure that it is really 4 
times as fast as the 8mm but definitely 3x is not stretching the truth. To say 
the least I am impressed with the 3570.  Of course, people say that I am easily 
impressed.

>>> Jason Morgan <jason-m AT JASON-M.DEMON.CO DOT UK> 5/6/98 5:20:35 PM >>>
Jeff,

We are currently using an IBM Magstar 3575 Tape Library with b/code reader.
It contains 60 slots and two 3570 Tape Drives with each cartridge holding
between 5Gb and 15Gb of data (approx 3:1 compression).  If you are doing a
lot of checking in/out this library is ideal as it takes about 20 secs to
checkin/out a volume compared to 3 mins on our old 7331 8mm library.

We use this 3575 library to back up an 8 node RS/6000 SP running AIX 4.1.4
and ADSM V3.

We like yourself used a 7331 Tape library for backing up our SP complex but
found the 8mm tapes unreliable even with lots of cleaning. We are now
considering other uses for our 7331 library such as PC/NT backups.

Further details can be on the 3575 library can be found at
http://www.ibm.storage.com/

Hope this information is helpful

Jason Morgan
Systems Administrator
B.G.C.C.B.C