Backups

Hello all

Very simple question -  does pg_dump/dumpall hit the server in terms of database performance? We currently do nightly backups and I want to move to hourly backups but not at the expense of hogging all the resources for 5 mins.

Pg_dumpall is currently producing a 1GB file - that's the combined size of around 30 databases and it takes around 5 mins to run.

Thanks
Rich