12V AMPERAGE REQUIREMENTS FOR HD4xxx Cards

Found this info from VGA Source.

Here's some info about what the HD4xxx cards that use from the 12v rail :-

Wattage and Current Draw -- Idle / Load

Sapphire Radeon HD 4670 -- 10W / 70W .. 0.8A / 5.8A

Sapphire Radeon HD 4770 -- 40W / 120W .. 3.3A / 10A

Sapphire Radeon HD 4850 -- 60W / 190W .. 5A / 15.8A

Sapphire Radeon HD 4850X2 -- 75W / 180W .. 6.25 / 15A

Sapphire Radeon HD 4850 CrossFire -- 125W / 210W .. 10.4A / 17.5A

Sapphire Radeon HD 4870 -- 60W / 165W .. 5A / 13.75A

Sapphire Radeon HD 4870 Toxic -- 70W / 185W .. 5.8A / 15.4A

Sapphire Radeon HD 4870 Toxic CrossFire -- 180W / 305W .. 15A / 25.4A

Sapphire Radeon HD 4870X2 -- 100W / 320W .. 8.3A / 26.6A

Sapphire Radeon HD 4870X2 Atomic -- 70W / 255W .. 5.8A / 18.75A

Sapphire Radeon HD 4890 -- 65W / 270W .. 5.4A / 22.5A

Sapphire Radeon HD 4890 Toxic -- 65W / 320W .. 5.4A / 26.6A

Note: this is what the video card uses, it does not include all other components in the system