From experience, all of the FX will run a little hot in terms of producing heat. I have an FX-8150. I don't overclock, but when playing a game on ultra settings the processor does produce a lot of heat. I have a liquid cooling unit that came with my cpu and it works fine while running 3.6ghz. If you are talking about the heatsink and fan that come with your 6350, you should be fine. Just make sure your case has good airflow. You will notice your room getting a little warm as you play though. That's normal for these cpu's though. If you want to ensure that your core temp stays within reasonable levels, you can also make sure to stick some good thermal paste on the unit. In some cases, it can lower cpu temps by up to 10 degrees. Your room will still probably get warm though.