OCCT (Overclock Checking Tool) is a tool to check your system stability by running 4 built-in tests, aimed at testing CPUs, GPUs and power supplies. In addition, OCCT also monitors in temperatures, voltages and fan speed, as well as system constants such as CPU Usage, Memory Usage and FPS for 3D testing.You can run a test indefinitely or limit it to certain duration. The results are shown in real-time and also saved as PNG image graphs to a OCCT folder structure, organized by date.The built-in system monitoring features (using HWMonitor) can be customized to automatically stop the test if certain values exceed a specified threshold (e.g. if your CPU is overheating).OCCT is designed for advanced users and overclockers, it offers little documentation and the interface can be a little confusing.