I would say it was the original Titan, the reason being that before it arrived we were using HD 7970s and GTX 680s on 28nm and suddenly we had a 50% or more increase in performance.
This in turn forced AMD to launch the 290 series which led to NVidia having to reduce the GTX 780 prices and launch the 780ti.
The reason I have said the Titan above has nothing to do with the fact it also comes with 6gb of vram or the compute functions as most people will not use these. It is just the huge boost in speed the Titan gave when compared to any other single GPU around at the time.
NVidia have now launched the Titan Black but compared to other cards that are now available like the 780ti or 290X, the Titan Black hardly stands out on performance alone and I think it can not be considered influential in the same way the original was.
This in turn forced AMD to launch the 290 series which led to NVidia having to reduce the GTX 780 prices and launch the 780ti.
The reason I have said the Titan above has nothing to do with the fact it also comes with 6gb of vram or the compute functions as most people will not use these. It is just the huge boost in speed the Titan gave when compared to any other single GPU around at the time.
NVidia have now launched the Titan Black but compared to other cards that are now available like the 780ti or 290X, the Titan Black hardly stands out on performance alone and I think it can not be considered influential in the same way the original was.