The test subject for the Thermalright HR-03 GT installation will be an XFX 8800GT 256Mb XXX Alpha Dog Edition. This is a slightly overclocked version of a standard 256Mb card, with "stock" clocks of 650/800. The 8800GT is installed in my Biostar TForce 570 SLI board, which places the top-most 16x PCIe slot much closer to the CPU socket than on single-slot boards. As can be seen in this "before" photo, when using a large cooler such as the Thermalright SI-128SE, there is simply not enough room on the back side of the card for the HR-03 to fit, much less with fan attached. Therefore I will use the other installation method for the cooler, placing the finned portion on the front of the card, facing down.
The factory cooler is of reference design, with copper core and aluminum backing plate / fins. It is held on with a total of twelve spring-loaded screws as it takes up the entire length of the card. There is thermal paste used as the interface on the core with thermal pads positioned to contact the eight memory chips as well as several power mosfets.
Note that I have previously removed the stock cooler and cleaned the factory thermal compound off, replacing it with high-quality Tuniq TX-2 paste. Since the TX-2 was used to record stock temperatures of the card I will also be using it with the HR-03 GT.
Next up, installation.