i knew i didn't like them for a reason but i have no choice...
in 1998 a company named 3dfx made the frist sli card proably using pci
The reason why they aren't around anymore is they made technology in cards a ahead of it's time but it couldn't be use becuase pc games sucked *** back then, from that it was very expensive(makes sense why buy something you can't use)
on the other hand ATI and Nvidia made cards that met only what the gamer need and it was cheap for people to buy
becuase of this they went out of bussiness. later on ati made their cross fire soultion which was pantent. Since there was no more 3dfx and they wanted to get back into the game the took the sli technology putting it in there new series 6 and 7 for pci express only.
i think you about it their dream of achiving more framerate and better picture killed them..