Advanced Micro Devices will delay the release of its dual-chip flagship graphics card, the Radeon HD 7990, to late August. The reasons for the delay are unclear, but what is important is that add-in-card partners of AMD do not seem to have plans to release their own-developed Radeon HD 7970 X2 ahead of the Radeon HD 7990, despite of expectations.

Although AMD has managed to release the world's first graphics processing unit (GPU) made using 28nm process technology, the Radeon HD 7900 "Tahiti", it has evidently failed to develop a dual-chip flagship graphics card powered by two of such chips. The arch-rival of AMD, Nvidia was several months late with its first 28nm GPU, but was quick enough to launch its dual-chip graphics board for enthusiasts in late April.

According to VR-Zone web-site, AMD has delayed its Radeon HD 7990 again and will unveil it at Germany's Games Convention (GamesCon) video game event in late August. It is noteworthy that this will be one of the first AMD product launches in years that will be made in Europe. In the recent years AMD launched its significant products either in the U.S. or in the Southeast Asia.

AMD Radeon HD 7990 graphics card is expected to carry two Tahiti XT (Radeon HD 7970) graphics processing units (GPUs) and 6GB of GDDR5 memory onboard. Thanks to two AMD Tahiti XT graphics chips, the dual-chip graphics solution will have 4096 stream processors, 256 texture units, 64 render back ends and so on. The novelty will have some kind of Turbo mode that will clock the chips higher when thermal design power allows. Besides, the reference design of 7990 will have four mDP display connectors as well as two dual-link DVI connectors to support up to six displays at once, something that Nvidia's GeForce GTX 690 cannot. What is surprising is that AMD is reportedly working on a special version of the graphics card with 12GB of high-speed GDDR5 memory onboard.

The exact reasons behind the delay are unclear, but besides natural challenges with installation of two Radeon HD 7970/Tahiti XT chips with ~200W thermal design power on the same board, VR-Zone claims that AMD decided to implement a rather exotic power supply circuitry. Instead of using two 8-pin PCIe power connectors, AMD decided to utilize four 6-pin PCIe connectors. Those four 6-pin connectors lead to a multiphase power regulation, divided into three groups. The major groups consist out of Tahiti XT (not the XT2, i.e. the GHz Edition), 3GB GDDR5 memory per core (clocked at 1.5GHz) and the PLX PCIe 3.0 controller.

The Radeon HD 7990 is projected to be more affordable than Nvidia's GeForce GTX 690, which official price-tag of $999 is exceeded in many cases.

AMD did not comment on the news-story.

Tags: AMD, Radeon, Tahiti, New Zealand, Southern Islands, 28nm, GCN