Before anyone asks, no, Advanced Micro Devices has no plans for a “reference” dual-HD 7000 card, not that we know of at any rate.
It may be because it sees no point in diverting R&D resources away from Sea Islands, especially with the many layoffs coming up.
VTX3D is just the latest partner brand to have taken matters into its own hands, believing there are still enough people who want overkill hardware.
The VTX3D HD7990 uses two Tahiti XT GPUs at 900 MHz clock frequency (925 MHz Turbo). The 6 GB of memory mentioned before run at 5.5 GHz and communicate with the chips via two 384-bit interfaces.
The only other details were mentioning pertain to connectivity: VTX3D decided on two DVI ports (one dual-link), HDMI and two mini DisplayPorts.