it will cost me as the same price of new 7870 non reference cards
so is this upgrade is good ?
is this card support Direct X 11.1 ?
is the difference from this reference card and non reference one is about cooling system and some over clock only ?
Note : I don't live in USA , so I cant use online shopping stores
Thermaltake 750 w +80 Silver
Seems like a good deal: I like reference boards as they are great for crossfire setups. However the issue with most reference cards is that they are basically gone from sale once non reference coolers start to hit the market. If you wanted matching cards to crossfire maybe later on, you might have to mix a HIS 7970 with a Asus 7970. Asus reference cards always tend to look a *tiny* bit different in terms of color.
I agree with Plasma, a nice overclock on your i7 will definitely help in some games.
Also remember the 7970 reference is extremely loud at load, its not as good as the GTX reference coolers (Which are pretty good for reference). You might want to look at an accelero solution if noise levels get too high.