identifying gpu

i recently purchased a used gpu from ebay claiming to be a gtx470
however it had major issues doing anything even resembling gaming so after a lot of googling i think it has been crossflashed from something else,it would seem the gtx465 was good for this,
anyway ive gone and flashed the asus gtx465 bios to it and it seems to be performing a lot better than it was

i just wondered if there was anyway to check if i have either corrected a bad flash or underclocked my card or something.
cheers