Display Tech, Cont: Fast HDMI

Moving on from multi-monitor applications, AMD has not only been working on technologies for multi-monitor users. Southern Islands will also include some video and movie technologies that will be relevant for single and multi-monitor uses alike.

With the 6000 series AMD upgraded their DisplayPort capabilities from DP 1.1 to DP 1.2. With Southern Islands AMD will be upgrading their HDMI capabilities. Currently AMD supports a subset of the complete HDMI 1.4a specification; they can drive S3D displays (the killer feature of 1.4a), but that’s the only thing out of 1.4a they support. HDMI also introduced support for 4K x 2K displays, but both displays and devices that can drive them have been rare. As displays start to become available so too does support for them with AMD’s products.

As per the relevant specifications, both DP 1.2 and HDMI 1.4a can drive 4K x 2K displays, but with the 6000 series the hardware could only handle such a display over DP 1.2. With HDMI it was an issue of bandwidth, as HDMI is based on DVI and uses the same TMDS signaling technology. At normal speed HDMI only has as much bandwidth as single-link HDMI (~4Gbps) which is not enough to drive such a large display. DVI solved this with dual-link DVI, whereas as of HDMI 1.3 the HDMI consortium solved this by tightening their cable specifications to allow for higher clocked transmissions, from 165MHz up to 340MHz.

It’s this higher transmission speed that AMD is adding support for in Southern Islands. AMD calls this Fast HDMI technology, which as near as we can tell is not any kind of HDMI trademark but simply AMD’s branding for high speed HDMI. With Fast HDMI AMD will be able to drive 4K x 2K displays over HDMI – which looks like it will be the common connector for TVs at those high resolutions – along with being able to support 1080P S3D at higher framerates with next-generation TVs. Currently AMD’s cards and TVs alike can only handle 1080P frame packed S3D at up to 48fps (24Hz/eye), or with a bit of hacking up to 60fps (30Hz/eye), which is fine for 24fps movies but much too low for gaming. As next-generation TVs add support for 1080P frame packed S3D at 120fps (60Hz/eye) Southern Islands products will be the first AMD products able to drive them over HDMI through the use of Fast HDMI.

The only remaining questions at this point are just how high does AMD’s Fast HDMI clock (they don’t necessary have to hit 340MHz), and if AMD will add support for any other features that higher bandwidths enable. AMD says that Southern Islands supports “3GHz HDMI”, which appears to be a misnomer similar to how we commonly refer to GDDR5 by its “effective clockspeed” in GHz, even though that’s not actually how it operates. In which case with Fast HDMI AMD may be referring to the maximum throughput per channel, which at 300MHz would be 3Gbps. 300Mhz would still be enough to implement features such as Deep Color (48bpp) over most current resolutions.

Display Tech: HD3D Eyefinity, MST Hubs, & DDM Audio Video & Movies: The Video Codec Engine, UVD3, & Steady Video 2.0
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  • GenSozo - Thursday, December 22, 2011 - link

    Style? Another possibility is that he has no life, a heavily worn F5 key, and lots of angst. Reply
  • Blaster1618 - Monday, December 26, 2011 - link

    One request when diving into acronyms (from the “quick refresher”), first one is followed by (definition in parenthesis) or hyperlink. Your site does the best on the web at delving into and explaining the technical evolution of computing. You maybe even able to tech the trolls and shills a thing or to they can regurgitate at there post X-mas break circle jerk. Never underestimate the importance or reach of your work. Reply
  • Concillian - Thursday, December 22, 2011 - link

    Page 1
    Power Consumption Comparison: Columns: AMD / Price / NVIDIA

    Presumably mislabeled.
    Reply
  • Anand Lal Shimpi - Thursday, December 22, 2011 - link

    Fixed, thank you!

    Take care,
    Anand
    Reply
  • Penti - Thursday, December 22, 2011 - link

    Will the new video decode engine either add software accelerated gpu or fixed function hardware WebM/VP8 video decode? ARM SoC's basically already has those capabilities with rock-chip including hw-decoding, TI OMAP IVA3 DSP-video processor supporting VP8/WebM, Broadcom supporting it in their video processor and others to come. Would be odd to be able to do smooth troublefree 1080p WebM on a phone or tablet, but not a desktop and laptop computer without taxing the cpu and buses like crazy. It's already there hardware-wise in popular devices to do if they add software/driver support for it.

    Nice to see a new generation card any how.
    Reply
  • Ryan Smith - Thursday, December 22, 2011 - link

    It's UVD3, the same decoder that was on Cayman. So if Cayman can't do it, Tahiti can't either. Reply
  • MadMan007 - Thursday, December 22, 2011 - link

    Pretty sure the chart on the first page should be labeled Price Comparison not Power Consumption Comparison.

    Unless perhaps this was a sly way of saying money is power :)
    Reply
  • descendency - Thursday, December 22, 2011 - link

    You list the HD 6870 as 240 on the first page ("AMD GPU Specification Comparison" chart) but then list it as around 160 in the "Winter 2011 GPU Pricing Comparison" chart. 80 dollars is quite a difference. Reply
  • Anand Lal Shimpi - Thursday, December 22, 2011 - link

    Fixed, sorry those were older numbers.

    Take care,
    Anand
    Reply
  • gevorg - Thursday, December 22, 2011 - link

    37.9dB is a horrible testbed for noise testing! WTF! Reply

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