Graphics Card Power Requirements

DarcoMate

Reputable
Jan 17, 2016
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0
4,510
So I have an Alienware X51 R2 with a Nvidia Geforce 660 in it however i wish to replace it with a better graphics card. I have the Asus STRIX GTX 970 4GB Graphics Card in mind however i'm a bit confused with the power requirements. From what i can gather from the volts and amps on my power supply i have a 329.55 watt power supply; 19.5V x 16.9A. Nvidia's site says the recommended power requirements for the 970 is 500 watts and the for the 660 450 watts.
Basically what i'm asking is can i get away with upgrading just the graphics card or do i have to upgrade my power supply too?

Additional Information:
Processor: Intel Core i7-4770
Ram: 8GB

Thanks!