I had calculated the efficency from the official TDP Value on wikipedia and the max. Hashing values of the Litecoin wiki.
The 7970 and the 7950 are identical efficent in theory.Why do you rate the difference as "nowhere near"?
Any examples or experiences? (So far i tested 7970, 5970 and 6870)
I recognised that some manufatures are better than others.
so i gett only 710khash out of the possible 800khash.
The 7950 costs about $210, draws 200w, and mines at about 660 Kh/s.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125414RThe 7970 costs about $280, draws 250w, and mines at maybe 700 kh/s if you are lucky.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814131468I've built a few dozen mining systems, and have never liked the 7970 for mining. It creates a lot more heat, and in my experience isn't any faster than a 7950 for mining. Most of my friends that have 7970's paid around $400, and don't use them for mining anymore.