I helped a customer who had a problem with a drive on his Mac. He has Drive Genius 3 installed on this Mac. DrivePulse was reporting a bad block with a specific block address. He also had TechTool Pro installed on this drive and TechTool was reporting a different block as being bad. He was perplexed and wanted to find the difference between TechTool Pro block addressing versus Drive Genius 3 block addressing.
Drive Genius 3 uses native block addressing which might be 512MB blocks or 4K blocks depending upon the drive. Drive Genius 3 scans all addressable sectors for bad blocks. Drive Genius 3 will report in the animation if there are any bad blocks or at the end of the scan the address of the bad blocks. If the scanning was done with spare bad blocks then Drive Genius 3 will spare the bad blocks and resolve it. If one or two bad blocks are found and have been resolved then the drive is fine to reuse as long as there are not anymore bad blocks found.