For me (around2003) a Malwarebytes scan is about 3 hours.
Superantispyware is a little over 4 hours.
It is taking anywhere from 1-4 seconds scanning literally every little background jpg. or whatnot on any given webpage. Unless I’m mistaken (and I do not profess to be a computer expert), there has got to be upwards of a million or perhaps tens of millions of possible individual items that may be in the system, and with having only looked at 84,000 in 2 hrs and 50 minutes, this scan could take days.
Dang, my old clunker Gateway must be really screaming, LOL.
When I run Malby, I have nothing else running, not even screen saver.
2 1/2 hours is normal for a full scan on C drive 32 Gb.
I don't usually scan the other partitioned drives on the primary drive or the secondary hard drive.
I figure if something is going to get you, it's going to get you on C.
On my wife's Win 7 machine, I scan the whole computer, both the primary SSD and the secondary hard drive because it just flies through it so fast, 45 minutes for everything.