Power On Self-Test — The Power On Self-Test (POST) is an automatic test that is run by your Mac’s hardware each time your Mac powers up, before Mac OS X is loaded. POST checks the basic functioning of RAM, Processor and boot ROM. |
I/O Check — I/O Check monitors your system for input and output (I/O) errors. I/O errors occur when a file either cannot be read from or cannot be written to the disk. This may indicate either that the file being written is corrupt or that there is a problem with the disk. |
Battery Test — Laptop batteries can be charged a large but finite number of times, or charge cycles. Once the battery has exceeded a certain number of charge cycles, it will begin to degrade, and will no longer hold a full charge or last as long. When laptop batteries are reported as having ‘poor’ condition, or are exhibiting other problems, you may need to replace your battery. |
Memory Test — RAM is very susceptible to damage. Static, heat and even normal air moisture can damage the RAM used to store your Mac’s workspace. The memory test uses a basic algorithm to test for basic problems with your RAM. |
SMART Test — SMART stands for Self-Monitoring Analysis and Reporting Technology. SMART technology monitors a drive as it is used and looks for unusual behavior. Problems found by this test indicate possible impending drive failure. |
RAID Status — RAID stands for Redundant Array of Independent Disks, and is commonly used to create redundant data storage or increase data access speeds. The RAID status test checks any internal RAID arrays for integrity errors. |
Volume Structures — A drive's volume structures consist of the data that tells the drive where to find its data. Damage to a volume’s critical data structures can result in lost or damaged files. This test checks your Mac's internal drives for errors in the volume structures. Many volume structures problems can be repaired using Apple’s Disk Utility or a third party utility such as TechTool Pro. |
Partition Map — The partition map is the portion of the disk that defines how the drive is divided up. Errors in the partition map can cause drives to appear to vanish. This test checks for errors with the partition map. |