AMD may be forced to postpone the launch of the next-generation Radeon HD 7000 graphics cards to 2012, says a series of rumors that have recently hit the Web and which blame the problems TSMC has with its 28nm chip fabrication node. AMD has promised time and time again that the Radeon HD 7000 series will arrive by the end of this year, but rumors regarding the delay of these GPUs started circulating since mid-September. Much like this latest Hardcore Hardware report, the previous rumors also blamed TSMC's low 28nm yields for the delay, as well as the foundry's limited wafer production capacity for this node. The large die size and complex design of the HD 7000-series GPUs is also a problem for TSMC, so it had focused its attention on building less complex 28nm chips. In addition to detailing the troubles faced by AMD with the production of the Radeon HD 7000 graphics cores, the report also comes to dismiss previous claims that suggested the Sunnyvale-based chip maker wanted to pair these GPUs with XDR2 memory developed by Rambus. Instead, AMD has decided to stick with GDDR5, but this time it will go for a 384-bit wide memory bus in order to improve the bandwidth available to the GPU. No other information about AMD's next-generation graphics card series is available at this point in time, but from the previous leaks that found their way to the Web, we now know that AMD's Radeon HD 7000 product family will use two different architectures. The first solutions to arrive will use the VLIW4 shader arrangement introduced with the Radeon HD 6900 series, and these will be known under the code names of Lombok and Thames. Later in 2012, AMD will also introduce the company's first graphics cards based on the Next Generation Core (NCG) architecture, which was detailed at the Fusion Developer Summit. This architecture will be used in the Tahiti GPU, that will also spawn a Radeon HD 6990 replacement known under the code name of New Zealand.