Cooling and Power
One element that is evidently becoming and increasingly talked about element with graphics cards is the level of power that they draw. Contrary to prior popular rumours, all of ATI's X800 boards, including the high end XT Platinum Edition, require only one internal power connector and in fact ATI have managed to buck the trend of increasing the power requirements as the Radeon X800 XT Platinum Edition actually requires less power than their previous generation Radeon 9800 XT board. Although we were unable to measure the power utilisation, according to statistics provided from ATI the X800 XT Platinum Edition had an average power draw of 76W whilst continually looping through 3DMark2001SE and 65W looping through 3DMark03 - the X800 PRO's power use in the same tests are 58W and 49W respectively.
One of the reasons for the relatively low power utilisation is that ATI still has a fair amount of knowledge gained in this area thanks to its mobile business and that knowledge has been directly applied to this high end chip for the first time. Of course, the use of the low-k option of TSMC's 130nm process is also going to help here, as opposed to the standard FSG option. However, with relatively low power utilisation you may ask if this will impact on the overall performance of the boards - the testing later in this review should answer that question.
The cooling of the board resembles that of the Radeon 9800 XT, with the very large fan and ducted copper heatsink, however it isn't exactly the same. As you can see, unlike the 9800 XT's cooling, the X800 heatsink purposefully avoids contact with the memory chips, as GDDR-3 are designed to run cooler than high speed GDDR or GDDR-2 and cooling isn't necessarily required - in fact the heat conducting from the core to a heatsink that touches the RAM could actually heat the modules up more than just having them passively cooled. The fan utilised proved itself to be a fairly silent solution on 9800 XT, as is the case here - however as part of the on-chip mobile technology utilisation, R420 features an on-die thermal probe which constantly monitors the temperature and different fan speed steppings are set in the BIOS to different temperature ranges, hence the fan will run at lower speeds when the chip is running cool and higher speeds when its hotter. The temperature and speed steppings are manufacturer configurable, so AIB's with different cooling options will have different settings. As with the 9800 XT, the cooling solution is well within a single slot configuration meaning that the board will physically fit within AGP small form factor PC's, including Shuttle systems.
