DisplayPort 1.2 takes stereo 3D into consideration

[DmitryKo]

The following WinHEC 2008 session takes a short glimpse of DisplayPort 1.2 update that seems to be developed by AMD/ATI.
GRA-583 Display Technologiesp

They aim to double the current bandwidth to allow 120 Hz displays to run at higher bit depths and resolutions and implement stereo signalling at the protocol level!

[DmitryKo]

Update: presentation from the CES 2009 Press Event
http://www.displayport.org/news-present ... _v3_09.pdf" onclick="window.open(this.href);return false;

Few key points:

• multiple independent video streams
• doubling of the effective bandwidth to 17.3 Gbit/s
• AUX channel bandwidth increases to host bi-drectional USB

In summary, DP 1.2 is able to host

1. two (L-R) 2560x1600 60 Hz video streams (or a single 1600p120 stream) at 30 bpp color;
2. one 3840x2160 60 Hz 30 bpp stream, or
3. four 1920x1600 60 Hz or 1080p60 streams at 24 bpp , etc.

over a single cable.


PS. For comparison, sample bandwidth required by certain resolutions, color depths, refresh rates and blanking methods, in Gigabit/s:

Code: Select all

	 	   		No blank   GTF	  CVT	 CVT-RB (1)
    60Hz 24 bpp						
1920	1080		 2.99	 4.15	 4.15	 3.33
1920	1200		 3.32	 4.64	 4.65	 3.70
2560	1600		 5.90	 8.36	 8.37	 6.45
3840	2160		11.94	17.10	17.11	12.80
    60Hz 30 bpp						
1920	1080		 3.73	 5.18	 5.19	 4.16
1920	1200		 4.15	 5.79	 5.81	 4.62
2560	1600		 7.37	10.44	10.46	 8.06
3840	2160		14.93	21.37	21.39	16.00
    120Hz 18 bpp						
1920	1080		 4.48	 6.22	 6.65	 5.14
1920	1200		 4.98	 6.95	 7.39	 5.71
2560	1600		 8.85	13.27	13.23	10.08
3840	2160		17.92	27.03	26.97	19.76
    120Hz 24 bpp						
1920	1080		 5.97	 8.29	 8.87	 6.85
1920	1200		 6.64	 9.27	 9.86	 7.61
2560	1600		11.80	17.69	17.64	13.43
    120Hz 30 bpp						
1920	1080		 7.46	10.37	11.09	 8.57
1920	1200		 8.29	11.59	12.32	 9.52
2560	1600		14.75	22.11	22.05	16.79

Note 1. CVT Reduced blanking as currenly defined by VESA only applies to 60 Hz signals, so 120 Hz with reduced blanking will need additional specifiation and testing updates.
Note 2. When directly driving a slim (cuircuit-less) 120 Hz monitor, the video card will probably have to dither down to 18 bpp, as current TN+film panels are only capaple of 6 bits per RGB color component.

See also this post for HDMI 1.3 and DVI discussion.

[Kimber]

Great information.

How long do you guess before we can expect to see displayport 1.2 in the market place?

[DmitryKo]

The v1.2 standard will be approved this Summer, so probably no earlier than 2010 Q1, and primarily in devices where the extended bandwidth is needed, such as 2560x1600 120 Hz stereo-3D or 3840x2160 60 Hz displays, should there be any by then.