Overclocking Monitor With CRU CRU (Custom resolution utility) is an app that’s been here for years and years. It’s free to use and works with GPUs from the big three – Nvidia, AMD, and Intel. Do note that, in case you encounter issues with your GPU, try overclocking with different tools. First of all, download the app and extract it to a new folder. Next, open CRU and click on the “Add…” button in the “Detailed resolutions” tab. Next, change the “Refresh rate” value to your desired OC value. We recommend starting with 5Hz higher than your monitor default refresh rate and going from there.