With or without backup/archive application (and which one)?

It depends on application.  For example, DP supports now DD Boost, but EMC based products can still leverage more out of it.  One would need to re-examine data today, but when I was checking PBBA market 2 years ago I had to ditch out HP because they had some limitation on number of files they could handle.  I would expect that was increased since as otherwise you would hit an issue.  Also, they GC process had to improve.  If you have chance, do text of both and pay attention to following:

- how do they act when filled up to 40, 50, 60, 80 and 95% in respect to performance and GC (yes, this means you will need to fill them up during test phase and you will need to pay attention not only to volume, but also number of files stored)

- how do they scale out for you (in terms of options and money)

- create list of must and nice-to-have and compare models - only you can answer what those are in your case

ok, thank you.

i was wondering if you have any competitive document for DD against HP?

EMC and HP might have it against each other, but for that you may wish to contact their presales.