At last, specifications of AMD's elusive Radeon HD 6970 and Radeon HD 6990 graphics accelerators made it to the internet, with slides exposing details such as stream processor count. The Radeon HD 6970 is based on a new 40 nm GPU by AMD, codenamed "Cayman". The dual-GPU accelerator being designed using two Cayman GPUs is codenamed "Antilles", and carries the product name Radeon HD 6990.
Cayman packs 1920 stream processors, spread across 30 SIMD engines, indicating the 4D stream processor architecture, generating single-precision computational power of 3 TFLOPs. It packs 96 TMUs, 128 Z/Stencil ROPs, and 32 color ROPs. Its memory bandwidth of 160 GB/s indicates that it uses a 256-bit wide GDDR5 memory interface. The memory amount, however, seems to have been doubled to 2 GB on the Radeon HD 6970. Antilles uses two of these Cayman GPUs, combined computational power of 6 TFLOPs, a total of 3840 stream processors, total memory bandwidth of 307.2 GB/s, a total of 4 GB of memory, load and idle board power ratings at 300W and 30W, respectively.