It's almost been running for 24 hours, and it's not done yet.
How many patterns does it do? Looking at the Arch Linux Wiki, there's two more patterns left.
I won't be using that drive for a while.
By default it does four passes. Which is 4*2, it has to read everything back.
Not sure I need to finish it, but I probably will let it finish anyways. Funny Arch Linux Wiki says it can take a couple of days for some devices, might take four days to complete.
It'll probably take over 60 hours. The first four operations took around 30 hours.