as big a market as nvidia hopes gpgpu will be it won't stake its entire market share on making something built for cpu work with gpu as a backup. Simply put they don't have the platforms available to push, why buy a latest and greatest mobo, stick in a cheap ass slow cpu just so you can get a system to do the work on a gpu. the majority of people will always buy a fast cpu for cpu based work.
My betting is "mimd" will simply for them be a marketing bs'ing way to say, we're doing what ATi do, shaders that can do more operations per clock instead of one shader per operation. But the mimd thing and sounding as much like a cpu builds on there whole gpgpu/cuda thing, which despite what they proclaim has limited to no use with very few and expensive apps that plenty of free apps around can do the same things, and better.
At a guess it simply won't be hitting 3tflops, the 4870 gets no where near with its peak theoretical and its peak theoretical includes all the core working at optimum, IE all shaders on each cluster doing an operation every clock which in reality it never comes close to for every single clock.
So anyway, its highly likely Nvidia will be switching to a more efficient size/power wise gpu a la ati and its clusters of shaders style approach, which begs the question of what 512 shaders could mean, 512 actual shaders of which all can possibly do a second operation would be very nice but a still damn huge, even for 40nm.
IT doesn't really matter, at this stage we all clearly know nothing, we can speculate all we want. What GT300 was supposed to be when it was thought up 3 years ago and what Nvidia need it to be are wildly different though. They've lost partners, lost exclusive partners by the shedload, they've lost market share, oem sales, they've lost a lot of money, sales are down due to the economy and due to ATi's prices their profits per sale are utter crap with partners making next to nothing. They have to, have to make a more competitive core in terms of yields and cost to build a card or all their exclusive partners will be flat out forced to sell ati cards to stay afloat.
the 280gtx, 285, 295 might be uber fast, the partners might love selling them for decent profit, but their bulk sales are on cards that might even be making them a loss. AFAIK ATi has won back a significant amount of the market share from Nvidia in the past 6 months and looks set to continue. ATi/AMD also have no financial worries anymore and a basically secured future of even cheaper cards with higher profits once they take over manufacturing themselves. Hell, theres even talk about Global foundries offering to build Nvidia cards, meaning every card both AMD and Nvidia sell means profits for AMD, which would be hilarious.
