The system hardware scan collects non-personal hardware details from your computer, such as your CPU, graphics card and memory amount. With this data Peacekeeper is able to tell you if your browser is performing as well as it should for your hardware configuration.
To obtain an accurate measurement of your browsers performance, try not to touch the Peacekeeper window while the benchmark is in progress. Ideally, Peacekeeper should be run in its own browser window without any other browser windows or tabs.