Id like all of you to look at your psu specs.
Then look at the PCI specs.
Then look at ATIs wanting people to oc this card, which is already at 294 or thereabouts.
PSUs say things like up to.
It will/does go over 300 watts.
But, it also has to be PCI compliant, so, at stock, it comes right under it.
A 5890 would only have either better cores and better electronics,caps etc for an even higher oc