To achieve the 21.6 Gbps rate, the per-lane data rate is doubled from 2.7 Gbps to 5.4 Gbps, over the four lanes that exist in the standard cable.For a single display, this enables ... a 3D display (120Hz) at 2560 x 1600.
DisplayPort v1.2 also includes improved support for Full HD 3D Stereoscopic displays:
-- Life-like motion using up to 240 frames-per-second in full HD, providing 120 frames-per-second for each eye
-- 3D Stereo transmission format support Field sequential, side by side, pixel interleaved, dual interface, and stacked
-- 3D Stereo display capability declaration Mono, Stereo, 3D Glasses