We have investigated if any of ATI’s partners will actually make an HD 4890 X2 card powered with two RV790 chips and most of them are negating that they plan do make such a card.
With a moderate clock, this card should be possible, it would
draw a lot of power as HD4890 has maximal board power of 190W but still a dual
card could be possible.
ATI said that it doesn’t plan to bring such a card, but we
were told before that partners could do it, but partners said that the
performance of dual X2 4980 card would not be enough to beat GTX 295 and
therefore doesn’t make much sense to make it.
At this point we are not aware that someone will make an HD 4890
X2 card, but if the partner decides to go this direction, ATI can provide
materials and some support to make such a project alive.