In the related art, even in computation of an application which has a resistance to a computation error in a computer system, since the computation error is accurately corrected, there is a problem that a power supply voltage or an operating frequency for realizing lower power or a faster speed cannot be variable in a large manner.In the invention, it is possible to solve the above-described problem by a computer system which includes a first processor and a second processor. In the first processor, at least one of an operating frequency or an operating voltage is variable. A detecting module which is operated by the second processor detects an error of the first processor. A determining module which is operated by the second processor determines at least one of the operating frequency or the operating voltage of the first processor.