Jeremy1998

I see the marks primary around the through hole components. It may be old dried flux residue from hand soldering. I've also seen this on old equipment. Sometimes I think it's sticky adhesive that simply collected very fine particle dust. Try rubbing it off with your finger or nail. You can also try rubbing alcohol and a Q-tip. Mineral deposits from water don't come off easy (I work part time as a janitor. Cleaning hard water deposits suck). If it comes off relatively easily then I doubt it's from water.

Yeah, the more I looked at it the more I thought the same. I just haven't soldered in years so I forgot about the flux residue. And I also thought of alcohol and q-tip, but for some dumb reason I thought that might hurt the card! Even though that's literally how you clean after soldering. Thanks for the reply, will try it and report back!
 
Edit: That's exactly what it was, it came off with just a little alcohol. Thanks so much for curing my brain fart!

on ubuntu or debian press the windows key and type disks. click the icon that comes up. This is the Gnome disks manager. This will open a program that will show all your drives. Select a drive then in the top right of the window is a menu button; from there you can choose SMART or benchmark.
Yes you can do full read & write tests from a live cd.