Power Consumption
When you read all those specs and see the two power connectors on the card you would be expecting that this video card needs its own fusion power plant to run. But it seems that this is not the case. NVIDIA recommends a 450W power supply for the 8800 GTX and 400W for the 8800 GTS. Now I am wondering if this takes into account the inflated numbers power supply manufacturers use, or if this is the real sustained power draw the card will need.
NVIDIA makes the following information available regarding power consumption.
These numbers are from a sampling of 130 applications. The dot in the middle of the bars is the average power consumption. Even though it is higher than previous generation products (of course). It is not as high as one would expect. NVIDIA has implemented a load of additional power saving features, for example parts of the GPU can be turned off while idle. This saves a lot of power and reduces the heat output of the card as well.
The two power connectors are required because according to the specification one power connector can deliver 75W. In certain peak situations this may not be enough, to make sure your wires do not overheat the second connector was added. The card will not run with just one power plug connected. Most board partners will include a 5.25" to PCI-E power adapter in the retail package to allow use on power supplies which do not have two PCI-E power connectors. The 8800 GTS will only use one power adapter.
NVIDIA has also increased the performance per watt. Compared to a Radeon X1900 XTX, the efficiency is 1.5 times better.