Fastest tool/application for testing hard disk

[Sp33dFr33k]

Before I sell my hard drives I want to make sure there's no bad sectors. What's the best/fastest tool/application for doing this?

Thanks

 

[ambit]

chkdsk /f /r ?
Then check the system event log when its done.

 

[tdg]

The only tool I can think of that will for sure tell you if you have bad sectors is Spinrite, but the manufacturers diagnostics or chkdsk would work fine for testing. Modern drives automatically find and mark bad sectors as bad and a lot of times they wont even show up with many utilities since the drive ignores them.