The Heatsink

The heatsink is made entirely from copper. Copper transfers heat better than aluminium, which allows NVIDIA to use a smaller cooler than would have been possible had they chosen to go with aluminium instead.

There are 22 U-shaped fins of various lengths. The shape of the fins give them roughly 3x the surface area of a standard vertical fin.

However, the entire heatsink isn't made from a single copper block. If you look closely at the fins, you can see that they were folded from a thin copper plate, like corrugated cardboard..

The folded copper plate is then soldered to the copper base. As such, the thermal conductivity of these fins will not be as good as it would have been, had the heatsink been made from a single copper block.

The Fan

The cooler is powered by a single Protechnic Magic 50mm fan placed to the right side of the cooler. According to Protechnic Electric's specifications, this is a high speed fan with two ball bearings and a power output of 2.28W.

This fan spins at 6,200 RPM and is rated with an air flow of 13.61 CFM or 0.386 CMM. It has a noise level of only 36.5 dBA and comes with automatic restart and locked current protection features.

Although the fan is not a blower fan, it acts as a blower, thanks to the design of the cooler and the shroud. Cool air is sucked from "above" the cooler and hot air exhausted out the top and the left side of the cooler.

The Memory Chips

ASUS used Hynix HY5RS573225AFP-14 memory chips in the EN7900GS TOP. These are 256 Mb (32 MB) GDDR3 SDRAM chips. With eight of these memory chips arrayed in pairs around the GPU, the EN7900GS TOP has a total memory capacity of 256MB. That should be more than enough for most games.

These memory chips have a rated clock speed of 700 MHz at core and IO voltages of 1.8V. ASUS has, however, overclocked them just a little to 720 MHz (1.44 GHz DDR). This gives the card an effective memory bandwidth of 46.08 GB/s, which is about 9.2% higher than that of both the GeForce 7900 GS as well as the GeForce 7900 GT.