Beyond3D take a further look at the ASUS EN7800GT TOP Silent Video Card:

As you might expect from a passively cooled part based around such a high-end SKU, ASUS have employed a hefty and rather innovative cooling design for the EN7800GT TOP Silent. We're used to seeing heatpipe solutions on passively cooled parts, where heat from the core is transferred to the top of the board where it disperses away from the graphics core - ASUS' solution takes this concept a step further, by transferring the heat away from the core and memory to a heatsink located completely away from the graphics board itself. In turn, this heatsink can be rotated through 360 degrees, so that the user can point it towards the part of the system where it will be cooled or allow the heat to dissipate most effectively - Usually over the CPU fan, so that the air pushed out from this will cool the heatsink in question.

The EN7800GT TOP Silent, as with most GeForce 7800 GT-based boards, has support for NVIDIA's SLI multi-GPU technology to allow for two boards to be run in tandem. Given the unique design of the parts cooling solution however, it has to be questioned as to the practicality of fitting two of these boards into most systems from both a space and heat dissipation perspective.