Emsa Disk Check is a dual-purpose utility, for disk checking (prescan and full disk reading) and also benchmarking. What it does, is scanning/reading the entire contents of a disk (CD, DVD or hard drive; or even floppy) and show any read errors that may appear, but also show drive speed information, progress statistics etc. It was designed with simplicity in mind, but usefulness for the user.
You can use it to do a full check of the surface of any disks, for example if you have just scratched a disk and want to see if it is still readable, or if you want to check all your cd library for time or usage related faults. You can also use it for drive benchmarking, easily comparing speeds through 'X' speed multiplier factor, in real conditions. You can also scan hard drives or even floppies - and get real condition performance information accordingly with drive performance but also with the way data is stored on it, which obviously impacts on overall performance. Make sur you clean the CD or DVD before doing tests, to remove dirt and ensure tests are accurate. Freeware.