ATI/AMD is successful with tis Radeon HD 4890. those cards are particularly designed for the overclock, and it will become a perfect solution if you modify the cooling system to make it more efficient and avoid having it permanently blowing. This is the first GPU that can easily reach and go beyond 1 GHz without massive mod. Many PC manufacturers expect to offer graphic cards with such clock frequency in their future hardware models. XFX already started to manufacture overclocked cards in small volume. They simply increased the voltage by 0.1 V and installed a better heatsink. Most manufacturers will also change capacitors for higher quality components able to last longer with such more demanding GPU. As a proof of concept, we overcloked our Radeon HD 4890 to 1 GHz, and performed two GLView benchmarks prior the crash of the card.
