The energy consumption level of high end video card continuously change power units requirements . It was considered that only standard PCI express 2.0 will allow to raise the applied power to video card through PCI express x16 slot from 75 to 150 W. In totality system with PCI express 2.0 support allows video card operation with power up to 300 W: half of power is ensured by interface connector, the other half is ensured by two additional power connector. The present PCI express 1.x specifications provide up to 75 W power through the interface slot.
PCI-SIG certification published preliminary electric specifications witch allow to exploit video card with 225-300 W power in systems with support TO PCI express 1.x. There was no additional information about changes in these specifications, But for sure this was with additional power connector. Video card with interface PCI express 2.0 can work in systems with PCI express 1.x support at the lowered speed. Now PCI-SIG demonstrates the readiness of power system .