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

Hi guys,

I'm considering buying a R9 290 or R9 290X. My main question is, for our specific purpose (password cracking) is there a relevant difference between these two models?

I was looking at specs and it says:

R9 290:
stream processing units 2560
Memory Type GDDR5
Memory Size(MB) 4096
Memory Interface 512 bits
Core Clock Speed(MHz) 947Mhz
Memory Clock Speed(MHz) 5000
RAMDACs 400


R9 290X:
stream processing units 2816
Memory Type GDDR5
Memory Size(MB) 4096
Memory Interface 512 bits
Core Clock Speed(MHz) 1000Mhz
Memory Clock Speed(MHz) 5000
RAMDACs 400

My questions is because there is a significant difference of price between them and there are some people that says that it's possible to unlock all the stream processors from 290 to turn into a 290X.

http://www.xbitlabs.com/news/graphics/di...eport.html

Anyone tested it? Recommends?

Or should I waste a few more bulks and buy the 290X?

Thanks.