Looking beneath Vader's helmet
After several minutes of unscrewing, prying, and coaxing, I was able to remove the 9800 GX2's metal shroud. Beneath it lies this contraption:
Like the 7950 GX2 before it, the 9800 GX2 is based on a dual-PCB design in which each board plays host to a GPU and its associated memory. Unlike the 7950 GX2, this new model has a single, beefy cooler sandwiched between the PCBs. This cooler directs hot air away from the card in two directions: out of the lower part of the expansion slot backplate and upwards, out of the top of the shroud.
Beneath the card, a ribbon cable provides a communications interconnect between the two PCBs.
And at the other end of the card, you can see the partially exposed blades of the blower.
Sadly, that's where my disassembly of the GX2 stoppedat least for now. Too darned many screws, and that ribbon cable looks fragile, so I chickened out. Presumably, on the PCB that houses the "primary" GPU, you'll also find a PCI Express switch chip similar to the nForce 200 chip that Nvidia used as glue in the nForce 780i chipset.
Before we move on to see how this puppy performs, I should mention one other trick it has up its sleeve: when paired with the right Nvidia chipset with integrated graphics, the GX2 is capable of participating in a HybridPower setup. The basic idea here is to save power when you're not gaming by handing things over to the motherboard's integrated GPU and powering down the GX2 entirely. Then, when it's game time, you light the fire under the big dawg again for max performance. Unfortunately, we've not yet been able to test HybridPower, but we'll keep an eye on it and try to give it a spin shortly.
Another thing we've not yet tested is quad SLI with dual GX2s. We can show you how a single GX2 performs today; we'll have to follow up with the scary-fast quad stuff later.