In most reviews of AMD's new Radeon HD 2900 XT you probably noticed that the card draws a fair amount of power - about as much as Nvidia's GeForce 8800 Ultra under load, even though its performance is more comparable to the GeForce 8800 GTS 640MB. Well, this high power consumption apparently failed to frighten the Swedish overclockers over at NordicHardware, because they strapped a liquid nitrogen cooler to their Radeon HD 2900 XT and managed to overclock the card from its stock core speed of 742MHz to a blistering 1211MHz:

That's exactly what Kinc did with the Radeon HD 2900XT and with the extra cooling the nitrogen provided a new top notch result was noted in core frequency, namely 1230MHz stable enough to run a round of 3DMark 03 which makes it the highest clocked graphics processor in the world so far. In order to reach this clock frequency a raise in core voltage was needed and when fed 1.53V the R600 put off a never before seen performance with a high-end graphics card. The card would namely have had managed even higher clock frequencies if it wouldn't have been for the heat; it was too hot! As mentioned, we were using a solid copper container filled with liquid nitrogen with a boiling point of -196°C and yet this wasn't enough to cool the R600 beast. At idle the copper container's temperature rose from -90°C to around -70°C which made it impossible to push the frequencies any further.

The fact that R600 undoubtedly at extreme conditions is too hot even for liquid nitrogen clearly shows why AMD chose to postpone the more extreme version of the Radeon HD 2900 series. The chip itself is very power hungry, but the power leaks in the 80nm processor are undoubtedly the reason for these extreme power consumptions and the even more extreme heat dissipation. This in itself is no good news for AMD, but we could look at it from the bright side as well. AMD has a thoroughly promising graphics processor and our tests indicate that the power leaks in the 80nm processor might be even bigger than anticipated. With this in mind, if AMD does a good job with its 65nm process, as rumored, it has shedloads to accomplish with the R600 core.

The fact is that we are looking at a 80nm graphics core that leaks power like no other but despite this it has no problems reaching higher frequencies with the right cooling. At 1211MHz which is the highest frequency we have proof of, the Radeon HD 2900XT performs an unbelievable 777GFlops (470GFlops at standard frequencies) which could be compared to around 40-50GFlops on todays quad-core CPUs.