Oh, man. Are you in luck. I swear by this program.
http://hddguru.com/content/en/software/2005.10.02-MHDD/
It will do a sector check of each sector, it's read speed, and also check for bad sectors. We use it all the time at my work, I don't think I could say enough good things about it.
Burn it as bootable iso. Select the drive you want to test. Type 'scan' then hit 'ctrl+enter' at the same time. Bam.
They make a GUI version of it called HDDSCAN also available on that site. It's not bad at all, but I definitely recommend the bootable version of MHDD.
It has a lot of other applications I have yet to test as well. For instance, if you have a bad sector, and you're SOL as it is, you can cut the partitions up to that sector, and see if you can plug it in via USB and have it recognize, etc. Good stuff.