We have SLI and crossfire, they work fine. But they are lacking in an area that could be implemented, with a little more work from both camps. Now you have an 8600GTS and a 8800GTX per say, just to say it ok. Now they can't work in SLI can they? The anwser is no, the reason is the 8800GTX would become an 8600GTS in the traditional way this is done. But what if Nvidia and ATI worked on the code and instead made it possible to mix and match like this, as long as feature set is the the same. Now the 8600GTS wouldnt do half the work, but what if it took care of say drawing the sky, or doing say 20-25% of the work, leaving the majority to the faster card, a load balancing, scheme, would work also if cards have diffrent memory ect, the faster gets more load to balance out the pair. Now that 8800GTX + 8600GTS would do better than say a stock 8800GTX would it not. What is keeping them from the next most obvious step in this technology.