In an interesting observation, it has come to light that AMD's soon to be released ATI Mobility Radeon HD 4860 MXM modules will carry the industry's fastest 5 GT/s GDDR5 memory chips made by Qimonda. From the part name on the chips, IDGV1G-05A1F1C-50X. One can infer "50X" to be the bandwidth per pin at reference speeds: 5 GT/s (5 GB/s in one direction). Across the 128-bit wide memory bus the M97 HD 4860 has, the chips can churn-out a staggering 80 GB/s memory bandwidth, never before seen on any mGPU board. In comparison, NVIDIA's G92b-based GeForce GTX 280M delivers 60.08 GB/s and AMD's own M98 RV770-based Mobility Radeon HD 4850 doles-out 56.8 GB/s.

The 5 GT/s GDDR5 chips are yet to be used by AMD in its desktop products. Development cycles have gone as far as including "40X" (4 GT/s) memory chips labeled IDGV1G-05A1F1C-40X on company-internal RV790 samples. Another DRAM major, Hynix had announced its plans to introduce 7 GT/s GDDR5 chips back in November 2008. The company is known to commence volume production of the 7 GT/s chip by the end of Q2 2009.

AMD today announced the world's first graphics processors to harness 40nm process technology: the ATI Mobility Radeon HD 4860 and ATI Mobility Radeon HD 4830. These feature-rich graphics processors redefine mobile PC entertainment with advanced capabilities including support for the latest Microsoft DirectX 10.1 games, a home theater-quality HD multimedia experience, and energy-efficient features for long battery life at work, at home or at play.