i think its a bug in the gpu-z program.
says here the 5550 and 6390 use the same id. maybe other cards do too.
maybe your card and the 5570 use the same id.
according to amd developer site the 675F id is a 6510 or 5500
here is my pic
note that mine actually says 5570 and yours says 5500 series.. maybe yours isnt a 5570, but 5550
you sure its a 5570?