It will be cutting it close,it could be up to 250watts it uses which is about 80% of what the psu can deliver.(i'm comparing some reviews for this,so it isn't rocket sience what i'm doing meaning you can't be sure i'm right!)
Reviews on the other hand measure at the wall socket so efficiency needs to still be applied.With 250watts would that be 250:100x~85=212.5watts. which gives more room=about 67% of usage.
The underlined still is true!