It was thought that the 3gb versions would not have SLI but the 6gb ones would still support SLI.
This looks like an NVidia marketing ploy to make even more money.
In the past if you had a card that was no longer giving the performance you wanted in games all you had to do was get another for SLI or CF as a cheap upgrade.
Now if you want to upgrade you have to spend a lot more on a GTX 1070 or 1080.
Im kinda in 2 minds about this, on one hand i think, oh well, Xfire / SLI has been broken so long its hardly an issue, then another part of me says, why do they have such arrogance to remove this feature forcing people to their higher products?
For the low end user who maybe upgrades rarely, the option to add a 2nd card to boost performance has always been a good thing, even if the support is bad, eventually a lot of titles get mgpu support, and on the back of the MS announcement of a kinda default mgpu driver, this just smacks of pure arrogance.
I do kinda see why they done this, they want people to spend as much money as possible with them, so they probably hope people will try the smaller cards, like them, eventually need more power and trade up for the bigger cards, its a smart move.
Dunno if it sits well with me though, i like having the option of adding a 2nd card if i need to, yeah support might be a bit hit and miss, but atleast the option is there.
Simply removing this option altogether is a bit rude.