Some specifications have shown up on a Chinese language website purporting to be those of the as yet unreleased AMD Radeon 7990, twin GPU graphics card.
The latest generation of AMD and still upcoming of Nvidia graphics cards have had a few specification lists released in recent months, some accurate, some not so much. So take this one with a pinch of salt - though it does look possible when compared with other contemporary cards.
Hexus has the translation of the original posting (Inpai.com.cn) which suggests the twin chipped 7990 will be very close to two 7970s on the same board. There is the classic slight core and memory frequency reductions, but across the board its mostly a doubling of the current most powerful AMD card available.
It still uses the 28nm Graphics Core Next Architecture and will also support DirectX11.1. It will feature 2x 4.3 billion transistors, 4,096 processors, a total of 6GB of memory (this makes sense as the last generation 6990 doubled the 6970's 2GB), 64 compute units and 256 texture units. The default core clock has been dropped from 925Mhz on the 7970 to 850Mhz, while the memory has been reduced from an effective clock of 5,500Mhz to 5,000Mhz.
The other available details are limited to the memory bus at 2 x 384 bits and the total Gflops of the card being 6,963. This is an increase of nearly 2,000 Gflops over the 6990.
It is thought that AMD is holding off this card till Nvidia releases its GTX 680 - which is expected to beat the 7970 in terms of raw performance - in order to allow the company to maintain the top dog position for GPU performance; even if it is with two cores.