SystemLoad is a diagnostic application assisting you in the detection of cooling or power supply problems with Apple computers. The tool can put a user-definable load onto one or more processors. This can help in diagnosing the following issues: problems with the cooling system or temperature sensors, problems with chirping noise caused by oscillating parts in the voltage supply circuitry of specific computer models, problems with battery units of portable computers.
When desired, the tool can put the processor(s) under the maximum load possible, generating the highest possible temperatures and highest load on the power supply. This way you can verify if all components (CPUs, sensors, cooling subsystem, power supply unit, battery unit) are working correctly when they are being pushed to their design limits. No installation is required, no administrator permissions are needed, nothing is changed in the operating system.
Note: Now requires OS X 10.11 or later running on a 64-bit Intel processor.