So it's twice as fast as your old card in a test that actually stresses the GPU. Why do you think it should be twice as fast again? 30 FPS in Ungine Heaven with "Extreme" settings is pretty darn good, do you have links showing this card getting 60 FPS at those settings?
Here are the page i used for reference.
http://forums.eteknix.com/threads/unigine-heaven-4-0-benchmark-results-leader-board.9127/
I used the same settings as them just to make it more easy to compare.
Hi Flowrider.
Did the 670 score like this 680 ?
Regards
Lasse