Defragging takes forever...

Last I've bought a 8 TB external drive USB3.1 for a backup of 12 million files and 6 TB.

I'm trying to defrag it but it looks that this will take weeks. Defraggler64 consumes practically 2 cores and per file it takes +/- 3 seconds.

Is this normal?

Find out if the drive uses Shingled Magnetic Recording ("SMR"), here's the WikiPedia page on it:

https://en.wikipedia.org/wiki/Shingled_magnetic_recording

If the drive uses SMR it can take a very long time to defragment it, one way to double-check and possibly get a faster defrag is try running the built in Windows tool Optimize Drives.

It is a LaCie d2 professional with a Seagate IronWolf pro 8tb disk, HDD type CMR. Moving large files to the end of the drive was done fast.

It looks that Defraggler needs a lot of time to find the next small file to optimize. It needs +3 GB but memory is not a problem, CPU is a i7-6950X.

I will try the built in Windows.