The official GT300/Fermi Thread

[570091D]

~2x as fast is the BEST case scenario. Shaders are being doubled but completely overhauled which should bring IPC but not necessarily.
Also there are many other parts of GF100 that could possibly bottleneck the architecture.

i would like to know which of the listed features will bottleneck this gpu.

Eventually, yes.
Full spec'ed and full speed? No.
6months after release? Maybe, most likely longer.
32/28nm shrink needed? Possibly.

http://www.fudzilla.com/content/view/15758/34/

i know it's fud, and i'm looking for corroborating sources, but they're stating a full range release (even the 2 gpu version). when/if i find anyone else with the same info, i'll share it.