I have a Radeon X600 HyperMemory(don't know what brand), and i've been experimenting with overclocking. It stays pretty dang cool, it came with my Dell Dimension E510. It only has a heatsink, and no way to read the temperature, so I was wondering if anyone else had a card similar to this and if they could tell me how high you can go safely. I've gotten to 470 core / 295 mem for each one, so 590 for the memory. I've found a good jump in performance with this, but I also want to know if this is truly stable (it seems so atm).