GeForce GTX 780 Ti  vs 690 

the fuckig problem with nvida is VRAM ! 970 3.5 gb 780 ti only 3gb yes this card are amazing buy i have sell my 780ti cuz i need mon vram for gta v nvidia gpu very good buy vram too bad like 680 2gb gtx 960 2gb nvidia kick ass in small time but for the long time buy amd sorry fan boys im bad in english 2 years later after you buy nvdia you need more memory this is why your bottleneck your system like gta v yes amd need more watt i know this amd driver are good people hate amd are so stupid stop fanboy

The least you will need for gaming is 2gb. 3gb is more than enough and it has more CUDA cores than the 690. If you get a gtx 780 Ti Classified k|ngp|n, you will get more performance than a gtx 980 and almost as much as the Titan but for like $200-$300 less.

Wrong. It's a sli, no matter what type it is, and the rules are the same. Every gpu in a sli work on the same data at the same time, so every chip must have a copy of this data in its vram for easy access. The sli bridge only coordinates the final data flow of every graphics card. (in fact the 690 is surclassed for 4K gaming for low memory)

That only applies to bridged SLI. not single silicon dual GPUs.

The VRAM available on the gtx 690 is incorrect. The real memory is 2Gb not 4Gb. This is because in sli the memory isn't summed, remains the same as the single card.

The VRAM is the only thing holding me back from getting the 780 Ti. More and more games are needing more memory, and I want to future proof my rig as much as possible, 3GB is just not going to be enough.

780 Ti is probably the better choice for now. The only true negative I see is less VRAM, but 3GB is still more than enough.

I think I will stay with my Evga factory Superclocked 780 TI, since it's about 15% overclocked (1007 base clock)