If your Mac is running slowly, crashing, or just generally misbehaving, the problem may be your disk. Both solid state and rotational hard drives can be the most error-prone components in your Mac. Slow performance, sudden application crashes, even computer crashes can be attributed to a malfunctioning hard drive.
Volume or Drive damage?
If you suspect a hard drive problem, it will be one of two things: 1) Volume Structures damage or 2) Physical disk damage. Volume Structures damage (or directory damage for recovering Windows users) refers to the data stored on a disk that keeps track of your photos, movies, music, and other files on the disk. The Volume Structures test in Techtool Pro can be used to identify this damage, while the Volume Rebuild tool can be used to repair it.
Checking Volume Structures
Volume Rebuild Tool – Disk repair in progress
Physical disk damage
If the volume structures test doesn’t find any problems, but you’re still thinking it’s a disk problem, then it might be the hardware of the disk itself. In this case, either the SMART check or the Surface Scan test can identify hardware problems with the disk. If failures are found with either of these tests, then the disk is physically damaged, and will need to be replaced.
Surface Scan test – scan in progress
SMART check – results
Of course, the problem could still lie elsewhere. For a description of the other tests and tools available to test your Mac’s hardware: