Recommendations for xfx 790i ultra psu

A quality 500watt would handle that fine!

The only XFX 790 Ultra I am aware of is an LGA 775 motherboard.

I assume you meant to say an XFX 79xx graphics card?

If so your XFX 550w power supply is fine. Any single graphics cards system can run fine on a 550w power supply. That XFX 550w unit is made by Seasonic and is very high quality.

Recommended power supplies by card.

http://www.realhardtechx.com/index_archivos/Page362.htm

Well he states that he has XFX790i ultra in the title! Which is the motherboard!
Motherboard by itself does not warrant PSU upgrade!

Actually he left the i out and since that's a discontinued LGA 775 board I just assumed he mistyped and meant a HD 79xx graphics card. It would be odd to upgrade to an obsolete discontinued motherboard.

He left it out in the post but not the title "Recommendations for xfx 790i ultra psu"

Good catch!  

Oh well, either way he is good with that power supply.