There are numerous free utilities that can provide vital statistics about your Mac. Most programs are able to run in the background all the time, however there are options for manual operation too.
So what do you want to target?
RAM – Mac OS X usage of RAM is quite efficient. Applications generally dynamically adjust the amount of memory they use, even if all your RAM is actively in use. A virtual memory system allows Mac OS X to use a portion of the hard disk to extend RAM, automatically swapping data between the disk and the physical RAM as needed. But of course there is a limit. You should keep an eye on how much RAM is being used. If the free RAM drops near zero, close windows, quit applications, or even restarting. Better yet, add more RAM where possible.
Disk usage – Hard disk capacity is always rising, so you’re not likely to run out of space. Nevertheless, running out of space can yield severe consequences. As your hard disk approaches its maximum capacity, your Mac will run more slowly as files become fragmented. Or data could be lost as your Mac has no space to save a file. And even more seriously, your computer may hang, crash, or fail to start up if it runs out of physical RAM and disk space to use for virtual memory.
To be safe, leave at least 10 to 15 percent of your hard disk space empty to provide breathing room for file storage, virtual memory, disk image creation, and other tasks. When you reach this figure, you should, delete unneeded and unnecessary files, and archive unused files to CD, DVD, or external hard drives. Your downloads folder is a good place to start!
More on Mac Maintenance soon!