TPU found some information that ASUS is working on a dual-GPU Radeon HD 5870 graphics card named "ARES", similar to the dual-GPU GeForce GTX 285 "MARS" graphics card the company created last year.
While the dual-GPU Radeon HD 5970 uses full-featured AMD Cypress GPUs (with all its stream processors and memory bus width available), ASUS will attempt to use the one disparity between an HD 5970 and two HD 5870 to its advantage: clock speeds. The Cypress GPUs in HD 5970 feature lower clock speeds (725/1000 MHz core/memory) compared to the single Cypress GPU on the HD 5870 (850/1200 MHz). Electrical constraints are probably the reason behind this. It is likely that ASUS will use stronger VRM circuitry to power the two GPUs to run at higher speeds, while also providing some overclocking headroom.