radeon 4830 vs. radeon 1950 pro (512mb)

Hello to everyone! I decided to change my GPU. I have now radeon 1950 pro (512mb) but i would like to replace it with a Radeon 4830. Can anyone show me a website or a link to see what are the “real” differences between these two cards. (speed, benchmark,) Or simply, just tell me…:slight_smile:
Thank you very much!