I was not defragmentation believer that much until using Outlook for a while and most of Outlook users would know how darned slow it is. I usually have to wait about >30s to be able to open the mail otherwise Outlook will freeze for 5 sec or so.

Now—since my machine has done disk defrag, now I could use Outlook as fast as Thunderbird [might not that fast, but waiting few sec comparing to a min is fantastic.] Ohh my god! it’s really helping. My outlook databases (3*IMAP) are about 800MB, 500MB and 200MB. FYI, whole defrag process is about 5 min or so for my 120GB with about 50% free of space.

I don’t know which one is the best, but I can say that Auslogics Disk Defrag is worth checking out. It’s free and fast, enough huh? If you have any advice, I would love to hear.