It all depends on a number of factors.
- Size of the drive.
- Amount of data on the drive.
- What sort of data you have on the drive.
- How often you use the drive.
- How often you defrag/optimize it.
I've got a 1T external drive that I was using for ages on an old system, about 3/4 full, and I use it constantly. I use it with a P2P program where I both share and download files. (I live in China - there's no way I'm going to sit around watching Chinese
television, so I download my favorite shows from back home (US) that are blocked by Chinese censorship from streaming online). Because of that it gets fragmented on a continuous basis.
I just added it to my Win10 system, and for the heck of it I ran the optimization and it is now at 3% of the 3rd pass.... and it's been literally 3 days.
Obviously this isn't a drive I'm going to have auto optimized once it's fully integrated into this system.
I'm pretty a-al about my drive setup and have a drive strictly for the system, one for program installation and several for data (documents, photos, videos). I optimize them all differently.
If you've never optimized, the first time is going to take a while. Don't take that as a sign of how long it will always take, then remove optimization completely. Once it is optimized, the weekly optimizations will keep it all nice and tidy for you and
won't take long (for most people in a normal use situation).