How many AMPS needed to run Radeon 6970?

[john5246]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814103182&cm_re=hd_6970_2gb-_-14-103-182-_-Product


At some point I'm going to upgrade to the Radeon HD 6970 2GB, how do I know that the PSU I'm going to buy has enough amps. On the product page it says:


550 Watt or greater power supply with one 75W 6-pin PCI Express connector and one 150W 8-pin PCI Express connector





This is the PSU I'm going to buy.


http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3276567&CatId=2533

It seems to have the right connectors, the 6-pin and the 8-pin, but is 45amps on the 12v rail enough for the HD6970?

How do I tell is the 6-pin connector is 75w like it wants, and that the 8-pin connector is 150w?

 

[mosox]

For a single card you can get this
SeaSonic S12II 520 Bronze
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151094
Or that one, semi-modular, it has a big disount right now (cheaper than the 550W version)
Antec TruePower New TP-650 650W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371021

All the PCIe power connectors are standard.

 

[vvhocare5]

John,
This is all basic math.

Watts are (roughly) current x voltage. In your case 45A x 12V = 540watts. More than enough.

The 6 pin connector is defined as 75 watts and the 8 pin is defined as 150W. Its just the way it is. All PCIe GPUs also pull power from the PCIe bus. Once that limit is passed you need auxillary power.

Yes you can add up all of the various wattages but the problem is the other devices dont report their consumption - so it doesnt really matter.

To either confuse or make this clearer, the onboard voltage regulators change our 12v to 1v (apprx) and pick up a bunch of amps. So our 75W input (12v x 6A) becomes 75A at 1V - but its all the same power....