after Cayman and Caicos prototype pictures surfaced, the guys from ChipHell Forums
also posted a picture of a prototype Barts XT card, which should end up designated as Radeon HD 6770 unless AMD decides to change its naming scheme at the last minute.
Bear in mind that we are still looking at prototype cards and that the actual retail samples might end up to be a bit different as we are pretty sure that it won't show up in the market with the pixellized cooler. Although the specs are still unknown, it can be seen from pictures that the card need two 6-pin PCI-Express power connectors, has singe Crossfire connector and has two DVI, an HDMI and two mini-DisplayPort connectors.
The card should have a 256-bit memory interface and, according to rumours, an 80% to 100% increase in memory bandwidth when compared to the previous generation.