DisplayPort 1.2, HDMI 1.4a, Stereo-3D and Eyefinity
Up till now the display controller of the Radeon HD 5000 series has been the most advanced one on the market, providing flexible connectivity options. Particularly, it allowed to connect up to three monitors to one graphics card (and special Eyefinity6 Edition products even supported up to six monitors simultaneously). Considering that Nvidia’s display controller supports no more than two displays at the same time, there has been no real need for improving the Eyefinity unit further. However, AMD has endowed the display controller of the Radeon HD 6800 series with new functionality to make it even more superior to its opponent. First of all, the new controller supports DisplayPort 1.2 for multiple-stream data transfers.
In other words any Radeon HD 6800 series card now supports up to six monitors simultaneously. Some of the monitors can be connected via DisplayPort in daisy-chain mode or using a special switch.
There are no special limitations as to the configuration of displays. You can use devices with different interfaces and resolutions. Besides, DisplayPort 1.2 supports a refresh rate of 120 Hz for 3D monitors. 3D panels can also be connected via HDMI because the Barts’ video controller complies with the HDMI 1.4a standard.
Additionally, the display controller of the Radeon HD 6800 series features a hardware color correction unit for displaying colors accurately on extended-gamut monitors. Summing everything up and adding the improved UVD3 video processor, the Radeon HD 6800 seems to be the most advanced multimedia solution available on the market right now, at least theoretically.
Universal Video Decoder 3.0
The third-generation video processor from AMD is interesting for its added support for hardware acceleration of DivX/XviD decoding and for entropy decoding of MPEG-2, which is added to the previously implemented decoding of H.264 and VC-1. The chip can also decode HD video in Adobe Flash 10.1 format. AMD claims the new video processor supports hardware decoding of Blu-ray 3D but that’s not as clear as it looks in the presentation.
The video processors of the Radeon HD 5800/5700/5600/5500 cards can formally decode two 1080p video streams simultaneously as required by the Blu-ray 3D standard, but things are somewhat more complicated in practice. Although the MPEG4-MVC codec is based on MPEG4-AVC (H.264), its decoding needs to take into account the relation between the two streams. In other words, although the previous-generation cards could decode two 40Mbps streams simultaneously, they could not synchronize them on the hardware to achieve the stereoscopic effect. Software-based synchronization is quite possible, though, but the previous-generation UVD was not qualified to decode and play Blu-ray 3D, which may mean that AMD just doesn't want to revise the software and/or BIOS for its HD 5000 series.
AMD also claims that the Radeon HD 6800 can score 198 points in the HQV 2.0 test, the maximum possible score being 210 points. The claim that the new solution is superior to the Radeon HD 5000 series in this respect needs checking out, of course.
Like its predecessors, the Radeon HD 6800 series supports Protected Audio Path and can bitstream 7.1 audio (192 kHz/24 bits per sample) with a bitrate up to 6.144 Mbps in AC3, DTS, Dolby True HD, DTS HD/DTS HD Master Audio, LPCM (Linear Pulse Code Modulation) and other advanced formats via HDMI 1.4a for further decoding on an external receiver.
Again, these innovations do not make the new graphics architecture from AMD something completely different from its predecessor. They only expand or add to the functionality of the Radeon HD 5000 series.
Now it’s time for us to finish the theoretical part of this review and move on to practice. We'll take a look at the new hardware starting from the senior model.