The T-Rad2 wipes the floor with the stock HD4850 heatsink. Plain and simple, it’s not a contest. With the HD4850 stock cooler at 875MHz I was only able to run loaded for 6 minutes before the system would crash due to temps. The T-Rad2 was able to keep the card stable at 875MHz indefinitely and even stretch its legs a bit more. Next up: swapping out the thermal material for Arctic Silver Ceramique.