Yes I misread. But actually this changes nothing. 280X stil uses the same, 550ti uses ~110W so total consumption is again over 350W and that is too much for 12V of your 550W PSU.
And by the way XFX is seasonic OEM so uses same parts.
A quote from one of web sites:
One more reference, but you can find a ton of them: http://forums.overclockers.co.uk/showthread.php?t=18346241
And by the way XFX is seasonic OEM so uses same parts.
A quote from one of web sites:
Quote
XFX Core Edition power supplies use a Seasonic platform
One more reference, but you can find a ton of them: http://forums.overclockers.co.uk/showthread.php?t=18346241
Quote
Unlike other PSU vendors even the entry level range is Seasonic.
So even the cheapest XFX is same as seasonic not like lame Corsair that uses cheap materials for budget versions of PSUs and let buyers think that they made a good deal but actually bought "same shit" as LC Power.Thanks for the tips m8
at least i learn something 
so the next ps should be XFX!!!