What is performance different between R9 290X and R9 290 [unlocked?]?

[LDA]

Awesome guys, thanks so much for your answer.

BTW, I remember that around 2011 HD 6990 was the TOP GPU to crack passwords, faster even in comparison with new models. Anyone have any statistics about HD 6990 and R9 290X? What is faster? Any idea about percentage?

Thanks.