I have to use pads because TIM won't fill the gap between the ram and the reference 4890 heatsink. I ran into a similar issue with an 8800GT. Fortunately the replacement cooler came with thermal pads. This time I'm not swapping for an aftermarket cooler with all the extras. I just want to be prepared for a worst-case scenario if the original pads are dried out or tear when the cooler's removed.