500W Power supply with an XFX 6790?

Afternoon chaps, I am planning on buying this graphics card: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

For my ALREADY BUILT system with this power supply: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I know the GFX card requires 2 6 pin connectors, seeing as my power supply only includes one 6 pin connector, i was planning on solving that "issue" with a cable like this: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

So, my question is, will these connections provide the power that the 6790 requires? my main concern is the wattage on the power supply, seeing as XFX recommends 500W or greater. I am pretty confident my power supply is reliable because i have had no problems in 4 weeks since i bought it, which within that time frame is when most PSU problems surface.

If it matters, this is the list of links of the products in my computer:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...