Geforce Titan - GK110 will be a consumer part

[JaD]

Some people have been spewing nonsense about VRAM requirements since the introduction of the GTX 680, just refrain from taking their opinion on the matter into consideration.

STEvil is right, with the available tools it's relatively trivial to discern vram usage; the problem (which i'm guessing Skymtl highlighted)is that VRAM occupation alone isn't enough to draw conclusions about it not being enough, because if texture buffers don't always get flushed and you can end up with a much bigger occupation than necessary: occupation should always be cross referenced with framerate with both a larger and smaller framebuffer.

The one and only situation where 2GB aren't enough is skyrim with excessive and pointless texture mods at 5760x1080+, or BF3/Crysis at silly SSAA+MSAA settings, at which point memory bandwidth and performance in general wouldn't keep up anyway.
For people who require that and the idiots who look at VRAM as a performance measure, there will always be properly overpriced cards with twice the amount of memory.