-Do you have rivatuner, install it and see what does it say bout your card 64bit or 128bit nv3x. this will determine wheather its a 5600 or no.
-maybe the card you have is this http://www.albatron.com.tw/english/i....asp?pro_id=56
minus the FAN. the fan is replaced with PNY fan (Dont know why though, and also is the BIOS).
-What do the stickers behind the card say?
-does the pcb of your card have a PNY logo anywhere. generally card mfg's put hir logo on the PCB. its not a fixed place though.