I normally do a full format when I purchase a new drive, exactly to check for any bad sectors - besides, the last 4 drives I've purchased have been for external storage, and processed with TrueCrypt... for security reasons, TC volumes shouldn't be quickformatted unless you're going to fill them to the brink right away.
As for data security, a normal non-quick format (
which just means zero-filling all sectors
- there's really no such thing as a "low-level format" anymore, after a drive leaves the factory)
is just fine
. People that still cling on to "military grade security multi-level formatting as prescribed by Gutmann" should check out what Gutmann himself
writes - things have changed since the old MFM drives the article was originally written for
Bottom line: a single zero-fill pass (or random-data if you insist) is good enough. If you suspect the NSA is after you, it's probably still good enough, but you might want to incinerate the drive just in case.EDIT 2010-11-16:
whoop, apparently a non-quick format doesn't
zero-fill sectors, so you do need a disk wiper - I still stand by a single-pass wipe being perfectly good enough, though.EDIT 2012-11-19:
whoop, you live, you learn. Quoting from Change in the behavior of the format command in Windows Vista
The format command behavior has changed in Windows Vista. By default in Windows Vista, the format command writes zeros to the whole disk when a full format is performed. In Windows XP and in earlier versions of the Windows operating system, the format command does not write zeros to the whole disk when a full format is performed.