Taking note of the news post below, maybe this information from Digitimes has already been answered?  Apparently NVIDIA was the board designers to find ways to cut costs on the G92 designs to better allow them to compete with the likes of the AMD HD 3800 series of cards.

Nvidia recently contacted its graphics card partners asking them to reduce the number PCB board layers used in GeForce 8800 GT-based graphics cards from ten to six in order to reduce manufacturing costs and so lower the card’s ASP (average selling price) in the market. The redesign would allow the Nvidia cards to compete in terms of pricing with AMD’s Radeon HD 3800 series products, according to sources at graphics card makers.

Although the Radeon HD 3800 series was launched three weeks later than the GeForce 8800 GT, Radeon 3800 demand has started to pick up, bringing the market shares of Nvidia and AMD from 90% and 10%, originally, to 70% and 30%.

If the PCB layers are reduced from ten to six, graphics card makers are expected to save more than US$10 for each card, which would allow the Nvidia products to go into price competition with those of AMD.

Despite the cost benefits, some graphics card makers are unhappy with Nvidia’s suggestion, pointing out that the chip maker is in effect asking them to do the job of improving the price/performance ratio of its products, while preserving its own profit margins.

Nvidia responded in saying that the redesign is only a suggestion which it believes is the best solution to meet the current market conditions. Card makers will not be forced to implement the change, the company stressed.