Checking for bad blocks without formatting My Mac tends to pause every now then when preforming simple tasks such as right clicking, opening menus and typing (It actually just froze when I started typing this question.).

I've read in a few places that this may be due to bad disk blocks, and that the best way to fix this is to format and overwrite the whole disk with zeroes. Obviously, this takes time and will destroy any data I have on the disk. Is there a way to check for bad blocks without formatting the drive, or even remap the disk to ignore those blocks (ultimately fixing it)?

My Mac is pretty recent (Mac Mini late 2011), so I doubt it has anything to do with low memory or swappage.
I'll answer the "bad blocks" tack and you can ask a follow on question if you still have slowness and you have concluded that it's not simply bad blocks. (Bad blocks is almost never a slow issue - since the system can remap blocks so rapidly, that you'd need rafts and rafts of them to actually impair I/O. If you do have bad blocks, they can corrupt some of the data on the drive and a reinstall not only fixes that, it forces writes to detect more bad blocks - kind of a win/win situation).

You need no extra tools to see the health of your drive.

Open Disk Utility and select the physical drive itself (not the Macintosh HD or whatever the partition/volume is) and select info.



If you record and watch the values under S.M.A.R.T. Status and see how they change over time, you can know pretty much anything that is detectable about storage degradation or partial failure.