Display Output, Video

When it comes to display output, each member of the '6 family, including R600, had a display output pipe that's arguably at the pinnacle of what's available on any consumer add-in board (AIB) today. On all of the GPUs in the family, display output is twice dual-link DVI, one of the ports supporting AMD's HDMI solution, and with both links per port protected by an on-ASIC set of keys and a hardware encryption block. That means not only do you get the benefit of each DVI port supporting HDCP for each of its two links out of the on-chip TMDS transmitters, but that you also get HDMI output over one of the ports on every board.

The hardware supports up to 10 bits per colour component for final output, should you have a display that'll receive it on the other side, and the analogue DACs for each output run at 400MHz and are capable of driving multi megapixel resolutions on analogue display hardware, should you have something capable there, too.

The HDMI solution is a novel one, the board working with an active DVI-to-HDMI adapter to transmit audio out over the spare pins in a dual-link DVI port (the current revision of HDMI that R600 supports -- 1.2 -- is analagous to single-link DVI), audio provided by an on-chip HD Audio controller. Yes, the new Radeon's are also rudimentary HD Audio controllers, too, and all audio processing for that controller is currently done on the CPU. That makes it no less a solution to provide protected path audio out via encrypted HDMI, though, using one of the DVI ports on the board.

It remains to be seen if shipping products based on R600 will come with the active adapter that provides the conversion, or a HDMI cable too -- both of which would be significant value additions for any '6 family product -- but we're not expecting all R600-based products to have the adapter in the box, which is a shame. Hopefully it's not too hard to find for sale online if that's the case, and it shouldn't cost too much when it appears.

Video Processing

NOTE: This part of the article is changed from the original, where it stated that all chips in the new '6 family contain UVD. That's not the case, R600 doesn't have that logic block and we're sorry for stating as such. At the end of the day it's our bad for grabbing the wrong end of a slightly misleading stick.

Almost all '6-family products and the GPUs that drive them contain a new video decoder block, which AMD worked with Tensilica to build, called UVD, or Unified Video Decoder (we're convinced it was called Universal Video Decoder at some point, but that's an aside). The UVD is designed to offload the entire decode process for H.264, H.263 and VC-1 motion video, at the maximum bitrates defined by the DVD, Blu-Ray and HD-DVD controlling groups, so that every SKU of this new generation of Radeon could perform (almost) full CPU offload acceleration for video playback for all three current optical disc formats.

The five major stages of the UVD are shown above, with the entropy decode supporting full speed CABAC and CAVLC for H.264, and VC-1's entropy encode scheme, entirely in silicon. Compressed video data is fed in to the unit at the front end of the block, and then that's passed out for post processing by other hardware solutions on-chip, which differ depending on the GPU in the family. R600 does all of the decode assist it's able to help with, and its post processing for motion video, on the shader core, implementing the filters needed entirely in shader programs that they can update and tweak as the driver matures. The current driver for R600 gets a score of 128 in the Silicon Optix HQV benchmark for SD DVD, showing that things are already pretty mature, at least as far as SD video goes.

RV610 and RV630 have an evolution of AMD's Avivo technology for post processing, where it's done in a slightly programmable block which the driver can set state for before the post processing takes place. We'll take a look at video quality in a separate article, resources permitting.