A benchmark computer is a computer used to provide a specific calculation of how fast a certain computing task can be accomplished with specific hardware. Benchmarking, a broader process of using actual hardware to calculate computing speed, can apply to figuring out CPU clock rates, processor performance, or operating system and software application agility.
Techopedia explains Benchmark Computer
Using a benchmark computer involves calculating the speed of a task using actual equipment rather than simulating a projected speed from specifications. This trial-based type of benchmarking helps engineers to understand how hardware performs in the real world and how well different tasks can be implemented with a given set of parameters.
Benchmarking with a benchmark computer is often done to analyze the peak performance of a processor, CPU or device. It can also help developers to understand challenges with various kinds of slowdowns, whether they are related to hardware or software issues. Some researchers now use an advanced analytic method of gathering many different outcomes from many different benchmark computers to get an average outcome. For a particular computer, running a benchmark process periodically before and after changes will help a user understand whether those changes have affected the speed of the device.