AMD's next-generation enthusiast graphics processor (GPU) is shaping up to be something more unique than expected. The GPU codenamed "Tahiti" is going to be bleeding-edge in terms of its feature-set. To begin with, there's talk that it will make use of PCI-Express Generation 3 (Gen 3) system bus, which will give it a mammoth 32 GB/s of system interface bandwidth. Next, Tahiti will use a number-crunching architecture that's a generation ahead of even the VLIW4 it released with Cayman. VLIW4 will make up for most of the HD 7000 series, but not the top-end Tahiti GPU, it will use what AMD is referring to as "CoreNext Architecture", which is expected to boost performance per square millimeter die area beyond even what VLIW4 manages.

The most recent piece of information is bound to shock and awe. Tahiti, it appears, will use the XDR2 memory interface. XDR2 is an ultra-high bandwidth and power-efficient memory bus that's competitive with GDDR5, maintained by Rambus, which is claimed by it to be a generation ahead of GDDR5. It's not like XDR2 will be exotic to AIBs, the XDR architecture is used in game consoles where the high-bandwidth offsets low memory capacity by allowing quick streaming of texture data. Rambus licenses XDR memory chip manufacture to notable high-volume vendors. Nordic Hardware compiled data from various unreliable sources to sketch out what Radeon HD 7900 series could look like.