Reliability
* 8mm - quoted at 500 passes but actual reliability is more on the
  average of 5-10 passes before failure.
* 3490/3590 tape - quoted at 5,000 full passes, 80,000 short passes..
  but actual customer experience is more like 100,000 passes.

Performance
* 8mm - 300-500 KB/sec
* 3590 - 9MB/sec
In addition, 3590 has quick search capabilities which leave 8mm in
the dust.

Capacity
* 8mm - 5GB
* 3590 - 10GB uncompressed (20-30GB compressed)

Price - I'm not a marketing guy but one customer told me he
pays twice for 8mm cartridges what he does for 3490 cartridges.
I don't know the exact cost of the 3590 cartridges but I believe they
are on the same order as 8mm cartridge costs.

What 8mm does have going for it are that the 8mm drives and
libraries have a lower entry cost and are more prevalent.

Greg Tevis

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> recommended two alternatives: A 7331-205 (8mm Jukebox with two tape-devices
> and 20 tape-slots up to 280 GByte capacity) and a Magstar 3590-B11 with ten
> 3490-tapes with a capacity up to 300 GByte. Now my questions:
> - What technology is better ?   8mm or 1/2 inch

Better is, of course, a religious issue. The 3590s are
considerably faster for data transfer, and the tapes are much
less susceptible to heat and decay, but are not widely
available in most Unix shops. The 8mm drives are more common, and
the media is more widely available in the Unix world, at the
expense of transfer speed (usually a tiny fraction of the 3590
speed).

> - Do you have any expirience with these boxes ?

Lots with the 8mm drives. You'll see average 300K/sec transfer
rates on these devices, and the media is good for at most 3-4
months in storage unless you have *really* exceptionally well
controlled environmentals in your tape vault. The 8mm tapes also
tend to stretch with use, which causes data loss.

I'd love to have a 3590 to play with...8-).

> - What about reclamation, do I really need two drives (should work with the
>   7331-205, shouldn't it) ?

You need at least two tape transports for reclamation to work
(tape to tape). I'd suggest at least 3 transports, to allow
migration to take place and still allow for user backup/restore
requests during the migration. If you have 8mm devices, you
should consider 1 to 2 more drives, due to the slow transfer
speed of the drives and the long duration of migrations due to
the high tape capacity.