a 7850 with half the shaders will do exactly half of that *MAX* (or 365). And when I say max, I mean max..
My Asus 7850 will only do 305@1050MHz with I=14. The card won't go any faster without crashing the driver.
My Gigabyte 7950 stock (no overclocking) will do just over 500GH/s each, the pair give an average of 1.046GH/s according to cgminer. Far, far better cards, considering I got them both used off the Bay of E for the same price I paid for the 7850 new.