There are many types of overclocking tests designed to ensure that any hardware that has been overclocked is still functioning properly. One of the most used overclocking tests is known as a stability test, and it checks on whether overclocked hardware is still accurately performing its core functions. Another test is known as a stress test, and it causes the hardware to use all its processing power to complete the test, revealing performance aspects such as the amount of heat generated, which might need to be confronted to use the hardware at the overclocked levels. Timing tests specifically measure the speed at which hardware functions when overclocked, measuring the rate at which data moves between components and the overall latency of key operations. There are specific tests designed to measure the temperature and voltage that is flowing to the processor, ensuring that the stream of power is consistent and that the temperature does not rise to an unacceptable level.
Nearly all the different overclocking tests, with a few exceptions, take a fairly long time to run to ensure that the testing is accurate and complete. In some cases, especially with overclocking tests for stress, this period of time can be 24 hours or more. Tests for the stability of a graphics card can take as little as a few hours. The tests are designed to run repeatedly to ensure that the results are as statistically accurate as possible, reducing the chance of anomalous false results that could lead to damage or data loss later.
One of the most used overclocking tests is the stability test. This is a test that forces the processor being overclocked to perform a series of logical operations to test whether it can perform those logical operations consistently. There are situations in which the processor will fail the test, usually because it has been overclocked too far, in which case the processor will need to have the changes downgraded. For a graphics card, a stability test can involve drawing mathematically complex images that are then scanned for errors, while a central processing unit (CPU) test could involve resolving the remainder of numerical Pi for several hours, checking the results against a pre-computed file.
Stress tests are one of the more important overclocking tests that can be performed, ensuring that the hardware can perform at the new overclocked level for an extended period of time without failing. These tests continually flood a processor with commands that must be executed, usually through a combination of all the different parts of the processor. For a CPU, this can be a test such as repeatedly solving a formula to determine prime numbers. Memory tests can include constant reading, writing and copying of data to make sure the increased speed does not cause errors. All the tests push the hardware with the sheer volume of tasks and also usually employ some form of error checking to make sure it also is stable and performing the tests correctly.
Determining the heat and voltage limits can be performed with a number of overclocking tests. These increase the processor load to almost 100 percent for an extended period of time and then measure the heat being generated and the amount of voltage entering the chip through the power supply. Too much heat means the processor will need a more effective cooling system installed, while voltage might be increased if the flow is low or inconsistent after testing.