This makes it relatively difficult to determine an exact temperature that is safe for your GPU. However, for modern GPUs, anything that is slightly below or equal to 75 o C is quite fine. If you want to be too cautious with your GPU, then I recommend you maintain a temperature of between 60 o C and 69 o C. General GPU Temperature Zones. Step 4: Start mining. Double click your Bat file to start the miner. The miner will start, run the setx commands to set those environment variables, initialize each of your GPU's, build the DAG file on each of your GPU's and start hashing away. Let it run for about 20 seconds and then click "s" to display your Hashing speed.