PostgreSQL 8.4, is it possible to install this with PT3?

[kraada]

It'll give the same results; it's based on your hardware not the size of your database.

[zubs1aa]

ok-

what if I radically redistributed te free space on drives (didnt touch any PT related or postgres.. but freed up a ton of C: and other space.

Will that affect it? Or is that again considered same hardware?

[kraada]

The thing that the auto tuning looks at most, I believe, is the size of your RAM. If you bought more RAM, then I'd say re-run it. Hard drive space doesn't actually matter for the settings PostgreSQL needs in order to work most efficiently.