The GeForce 7600 and 7300 became readily-available, affordable video cards almost overnight.  A major secret to the success of these cards was due to the fact that the GPUs were designed to use the old PCB designs from GeForce 6200 and 6600.  Once again, NVIDIA will take advantage of this mentality again with the next generation G86 and G84 video cards scheduled for release this quarter.

Was it surprising that images of the GeForce 8600 that have been "leaked" out to the internet look identical to GeForce 7600s, or for that matter GeForce 6600s?  It shouldn't be, as that was sort of the whole point in making G84 and G86 pin compatible with G73, which was already pin compatible with NV40. 

G86 and G84 (G8x family) GPUs do have some major differences between G73 however.  For starters, the main G73 power rails run at 2.5V -- on the G84/G86 these rails run at 1.2V and 1.8V.  The G73 clock generator runs at 1.3V while the G8x family clock generator runs at 3.3V.  Additional dead pins have also been allocated on the G8x family for higher density memory.

One of the bigger surprises of the G8x family is the support for more than 4 GPUs, at least in the design.  It seems pointless to put a low or mid range GPU into SLI mode when a high-end card can usually produce better performance at lower cost.  However, the G8x family design kit touts an interface for "more than 4 GPUs."  Given the unified shader architecture of the GeForce 8000 family, it would be pretty safe to say this additional functionality is probably reserved for some sort of physics project.