Do i need a PSU upgrade for radeon hd 7950?

i have a intel i5 2500k 4.5ghz

sapphire radeon hd 7770 vapor X

8 gbs of ram

western digital cavier black 500gb hard drive

i have this PSUhttp://www.newegg.com/Product/Product.aspx?Item=N82E16817207013&Tpk=xfx%20core%20550

should i upgrade my PSU first then get the radeon hd 7950?

550w - 650w is more than enough for single GPU builds. You only need more power (650w and up) when you're using 2 or more GPUs

enjoy, the 7950 is a beast of a graphics card.

550w - 650w is more than enough for single GPU builds. You only need more power (650w and up) when you're using 2 or more GPUs

krisroe_213

Quality 500-650w units can power most dual card setups.

You'll be fine. I've got my 7950 running on a 500w Corsair PSU.