Other than taking up two slots, this card requires two independent connections to the power supply. This is because the current AGP slot with single power connection is unable to supply enough current to power the 222 million transistors. Hopefully the PCI Express version will be able to solve this problem. nVidia recommend at least a 480W power supply to use with 6800Ultra. However, the power source must come from two independent 12V rails, and if only one power connection was used, the driver will warn the user after booting into Windows.



Link: HardwareZoom