If you are meeting someone to buy a used GPU, you can run FurMark Portable from a thumb drive on their system to ensure the card doesn't crash under load.
→ Install latest GPU driver. FurMark Portable doesn’t bundle OpenGL drivers.
FurMark Portable is a standalone, self-contained version of the FurMark GPU stress testing tool. It doesn't require any installation, allowing users to run it directly from a USB drive, CD, or any other portable storage device. This makes it an ideal choice for IT professionals, gamers, and enthusiasts who need to test GPU performance on multiple systems without leaving a footprint.
Often referred to as the "power supply killer" or the "GPU furnace," FurMark is legendary in the hardware community. The portable version takes this heavy-hitting tool and strips away the installation requirements, giving you instant access to one of the most intense GPU stress tests available—all from a USB stick.
Example batch script to log results from multiple GPUs: