The cooler of the Radeon X1800 GTO differs somewhat from the one installed on the Radeon X1800 XL, but its concept (see our article called ATI All-In-Wonder X1800 XL: All I Want? for details) has remained the same. The graphics processor gives its heat to the cooler’s copper sole which is then evenly distributed in the ribbing by means of two U-shaped heat pipes. The ribbing is blown at by a small fan. The air stream then also cools the heatsink on the power regulator’s MOSFETs and leaves the card. The cooler is covered with a flat aluminum cap.
The cooler on the Radeon X1800 XL had a 4.2W ADDA fan (0.35A, 12V) which was criticized for being noisy. The new cooler has got a larger and quieter 3W fan (0.25A, 12V) which uses a 3-pin connection with a separate line for the speed sensor. The speed control system is the same as in the entire Radeon X1800/X1900 family. You can also control the speed of the fan manually by means of RivaTuner.
As usual, there’s a layer of very thick dark-gray thermal paste between the cooler and the GPU die. The memory chips give their heat to the aluminum casing of the cooler via thick rubber-like thermal pads.
The new cooler installed on the Radeon X1800 GTO will probably be slightly more efficient and less noisy than the one they used on Radeon X1800 XL. We don’t expect any miracles, though, because the heatsink has remained almost the same plus this system doesn’t exhaust the hot air out of the system case.