It varies from card to card. You'll find the babies of the range don't have it, yet the more powerfull cards do. I have an Nvidia 6200 card, which has the solder points on the board for the socket, but no socket. It works perfectly without it.
So if the manufactures never fitted the socket to the board, chances are you wont need it!
HTH
Chris
Thanks Chris, that's what I expected but it's good to hear it from someone with real experience.
I'll put it all together on the bench tonight and see if it flies.
Peter