I am currently wiping a hard disc for ebay with Darriks Boot and Nuke. It was reeeeaaally slow. Then I found a short snippet in a a forum recommending 1.0.6 instead of 1.0.7. you can find an installer for 1.0.6 by searching for dban-1.0.6_i386.exe

That really solved it. from 800hours down to 5hours