Can i Crossfire two HD 6670s?

[axew]

Hello, i have a HD 6670 as my current GPU. Since my motherboard is SLI/Crossfire capable i was thinking of getting another one for Crossfire, can i do that with HD 6670?
Also if i can, can two HD 6670s beat a card such as HD 6790 or HD 6850 in performance? I can't find any reviews for HD 6670 crossfired on google.

My CPU is Athlon II x3 455 with unlocked 4th core and OCed @ 3.8 GHz and my PSU is Thermaltake Litepower 500W.

 

[Helltech]

What is your motherboard? Also Thermaltake makes really bad PSUs, sorry to say. So while it is rated to be good enough for CF 6670s, it might not actually be able to cope.

Two 6670s would be around the performance of a 6790.

 

[axew]

Well my only PSU options are Chieftec, Cooler Master, Thermaltake and LC Power.
Not much other PSU brands in my country.They are not the best but are better than Codegen at least .
Also is there any review for HD 6670 Crossfire??