Information Technology Reference
In-Depth Information
Testing
There are various ways of stress-testing a Mac, but the easiest way is as fol-
lows. Before starting, be sure to save any open files and close any unnecessary
applications. If you're using a portable Mac, attach the power cord.
Before starting, find out how many processor cores your Mac has. Unless
you're using a Mac Pro desktop system, the answer will be either two or four.
To see a quick trick to view the number of cores in the system, check out
Tip
in the CPU performance graph; each represents a core of your CPU.
Open a Terminal window (open Finder, select the Applications list, and then
in the list of applications double-click Terminal within the
UTILITIES
folder), and
type the following at the command prompt:
YES > /DEV/NULL
Then hit
COMMAND
+
T
to open a new tab in the Terminal window, and type the
command one more time. If you have a four-core processor, repeat the step
twice again so that a total of four tabs are open and running the command.
If your computer has eight cores, then, yes, you've guessed: you'll need to do
this eight times in total so that Terminal is running the command within eight
tabs.
The
YES
command merely creates a stream of characters, but it does so as
quickly as it can, to the extent that it soon consumes all the available process-
ing power. Elements after the command direct the output of the
YES
command
to
/DEV/NULL
, which is like a black hole in the system that consumes as much
data as is thrown at it.
Terminating the Test
Wait for a few minutes. You'll probably hear your computer's fans start to
spin. This is normal, as is the computer getting hot. You might also find the
computer becomes a little sluggish when responding to your interaction.
If the computer hasn't crashed after five minutes, terminate the test by closing
the Terminal window (don't worry about any warning that doing so will termi-
nate currently running apps). If your Mac crashes or freezes up before you
terminate the test, it's very likely your computer has a fault that requires
repair.
