
Originally Posted by
P0w3rM0v3
they can if they really wanted to

Even if they wanted they cant unless they redesign the chip and the width of the bus since its using 384bit and 64Mb GDDR5, either you get 1.5GB or 3GB per GPU since you need to add a pair of 64Mb to get it to work. 256bit (slower) or 512bit ( more expensive and a bigger die, increases manufacturing failure ) can also go with 2 or 4GB.
Theres a whole lot of explanation on memory allocation for different width sizes on the bus, Im pretty sure you already know about this issue but would just like to get 2GB instead of 3GB per GPU.
Then again this will be a very castrated (Full shader cound, significantly lower clockspeeds) GF110 just to make the 300W PCIE 2.0 spec, not worth the upgrade considering you already have 4x GTX580's