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PRTs, DirectX 11.1, Eyefinity, Stereoscopic 3D, And More

AMD Radeon HD 7970: Promising Performance, Paper-Launched
By , Igor Wallossek

The Tahiti GPU isn’t just an improved gaming and compute engine. AMD is introducing a number of new features to its Southern Islands-based product line:

DirectX 11.1, OpenCL 1.2, and DirectCompute 11.1

Windows 8 is slated to include DirectX 11.1, and the Radeon HD 7970 supports it. You can read more about the new features of Direct3D 11.1 on Microsoft’s Dev Center website.

Partially Resident Textures (PRT)

PRTs present a nifty way to take advantage of Tahiti’s virtual hardware memory, treating the card’s GDDR5 like a managed texture cache. PRTs allow for at least two interesting benefits: reducing stutter and texture popping, and facilitating hardware-managed megatextures (similar to the ones used by id, the developers of Quake and Rage).

As textures are fetched for rendering, only the visible segments of that texture are loaded into memory (in 64 KB chunks). But the magic occurs when a texture call is missed. In that case, the GPU can give feedback to the application and ask for further instruction, giving the application unprecedented control to choose the textures it wants to load and determine how to prioritize as it moves forward. In turn, the GPU can display a low-resolution texture before the higher-resolution version is loaded to (ideally) reduce stuttering.

Eyefinity 2.0, Display Support, and Desktop Enhancements

According to AMD, the Radeon HD 7970 is the first graphics card able to provide multiple simultaneous independent output streams, called Discrete Digital Multi-Point Audio (DDMA). This means that each attached screen can output its own unique audio signal. Although this isn’t a significant value-add to most enthusiasts who shy away from monitor-attached speakers in favor of discrete speaker systems or headphones, it does have an interesting application to multi-display video conferencing.

The Radeon HD 7970 also introduces simplified ultra-high-resolution display support. To date, 4K-pixel displays required multiple inputs, but the Radeon HD 7900 series can purportedly do this from a single connector now using 3 GHz Fast HDMI or DisplayPort 1.2 HBR2.

Finally, some notes about upcoming features planned for the Catalyst Control Center driver. AMD says that, in February 2012, the 12.2 driver will offer custom desktop resolutions, a feature it says that Eyefinity users asked for since day one. Other enhancements include preset manager improvements and the ability to drop the Windows taskbar on a preferred display in a multi-monitor environment.

Stereoscopic 3D Enhancements

The first stereoscopic 3D announcement ties in directly with Eyefinity, but it’s not specific to the Radeon HD 7900s: the Catalyst 11.12 driver includes Eyefinity support for HD3D, and the already-available Catalyst 12.1 preview driver includes CrossFire support for both HD3D and Eyefinity, lifting one of the biggest detractors from 3D gaming on AMD graphics cards. Rendering in stereo is incredibly demanding, and CrossFire could definitely help. Until now, though, it simply wasn’t an option.

Radeon HD 7970 is the first graphics card to support the aforementioned 3 GHz Fast HDMI standard, capable of frame packing a 1080p stereoscopic 3D signal to televisions at 120 Hz, or 60 Hz per eye. Unfortunately, this doesn’t work on existing televisions. The display must support Fast HDMI explicitly. On a side note, the Radeon HD 7970 also supports 60 Hz (30 per eye) stereoscopic gaming over standard HDMI 1.4a, although we’re not sure how much of a difference it makes compared to the current 48 Hz implementation.

Finally, it’s worth noting that Microsoft will include a Stereo3D API in Windows 8, and AMD’s Radeon HD 7970 is already claimed to support it. The hope is that this vendor-agnostic solution will embolden more developers to get on-board.

UVD and the new Video Codec Engine (VCE)

AMD added dual-stream HD+HD acceleration to its newest iteration of the Unified Video Decoder (UVD), but that's the only change to UVD's decoding feature set. There is something new to talk about on the encoding side, though, and that’s the Video Codec Engine (VCE). Although AMD isn’t specific about VCE’s implementation (making it tough to compare to Intel’s Quick Sync), it does call the feature a multi-stream hardware-based H.264 encoder. Chris Angelini predicted the arrival of something like this nearly a year ago in his Sandy Bridge launch coverage.

The thing is, limited to H.264 encode acceleration, VCE isn’t as comprehensive as Quick Sync. AMD claims that the encode pipeline is capable of working faster than real-time. However, it’s not as scalable on its own as it would be if you were using VCE with the GPU’s compute improvements in parallel.

To that end, the company recommends using VCE-only on lower-end graphics cards, or perhaps in mobile environments where the power savings of fixed-function logic has a big impact on battery life.

The hybrid mode, shown below, is more interesting. Because it involves compute resources (the ALUs), power consumption increases dramatically. The programmable hardware takes over a greater number of encode tasks, while the VCE retains entropy encode duties.

Although we’d love to compare VCE to Intel’s Quick Sync, or even Nvidia’s CUDA-accelerated encode performance, this is yet another components of the Radeon HD 7970 launch that isn’t ready for testing. In fact, none of the features discussed on this page could be tested to make sure they work. AMD simply couldn’t supply us with the software tools able to exploit the virtues of what it says its GPU can do.

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Top Comments
  • 42 Hide
    danraies , December 22, 2011 3:49 AM
    cangeliniStart treating your SO super-nice and ask for one for Valentine's Day!


    If I ever find someone that will buy me a $500 graphics card for Valentine's Day I'll be proposing on the spot.
  • 30 Hide
    thepieguy , December 22, 2011 3:32 AM
    If Santa is real, there will be one of these under my Christmas tree in a few more days.
  • 25 Hide
    cangelini , December 22, 2011 4:01 AM
    ZombeeSlayer143WOW!!! I love the conslusion; all of it, which basically is interpretted as "I'm biased towards Nvidia," and trys [desperately] to say don't buy this card! Has the nerve to mention Kepler as an alternative; right, Kepler, as in 1 year away. The GTX580 just got "Radeon-ed" in it's rear. I'm not biased towards either manufacturer, just love to see and give credit to a team of people with passion, vision, and hardwork come together and put their company back on the map, as is shown here today with AMD's launch of the 7970. It's AMD's version of "Tebow Time!!"


    Not at all, actually. It offers great gaming performance, and for everything else...we have to wait, because it's not fully baked yet. They say fools rush in. This thing launched today. We were given less than a week with it. It won't be available to even *buy* for another three weeks. Are you telling me you're ready to crown a paper winner, and you're not biased? Please...
Other Comments
  • 30 Hide
    thepieguy , December 22, 2011 3:32 AM
    If Santa is real, there will be one of these under my Christmas tree in a few more days.
  • 12 Hide
    mi1ez , December 22, 2011 3:40 AM
    Damn, that's a good looking GPU!
  • 11 Hide
    cangelini , December 22, 2011 3:40 AM
    a4mulaFrom a gaming standpoint I fail to see where this card finds a home. For 1920x1080 pretty much any card will work, meanwhile at Eyefinity resolutions it's obvious that a single gpu still isn't viable. Perhaps this will be something that people would consider over 2x 6950, but that isn't exactly an ideal setup either. While much of the article was over my head from a technical standpoint, I hope the 7 series addresses microstuttering in crossfire. If so than perhaps 2x 7950 (Assuming a 449$) becomes a viable alternative to 3x 6950 2GB. I was really hoping we'd see the 7970 in at 449, with the 7950 in at 349. Right now I'm failing to see the value in this card.


    I'll be trolling Newegg for the next couple weeks on the off-chance they pop up before the 9th. A couple in CrossFire could be pretty phenomenal, but it remains to be seen if they maintain the 6900-series scalability.
  • 7 Hide
    cangelini , December 22, 2011 3:41 AM
    thepieguyIf Santa is real, there will be one of these under my Christmas tree in a few more days.


    Hate to break it to you, but there won't be, unless you celebrate Christmas in mid-January.

    Start treating your SO super-nice and ask for one for Valentine's Day!
  • 16 Hide
    Darkerson , December 22, 2011 3:48 AM
    Well I know what I want at tax time :D 
  • 42 Hide
    danraies , December 22, 2011 3:49 AM
    cangeliniStart treating your SO super-nice and ask for one for Valentine's Day!


    If I ever find someone that will buy me a $500 graphics card for Valentine's Day I'll be proposing on the spot.
  • -3 Hide
    Zombeeslayer143 , December 22, 2011 3:56 AM
    No hard feelings to the author...thanks for the review nonethless..
  • 25 Hide
    cangelini , December 22, 2011 4:01 AM
    ZombeeSlayer143WOW!!! I love the conslusion; all of it, which basically is interpretted as "I'm biased towards Nvidia," and trys [desperately] to say don't buy this card! Has the nerve to mention Kepler as an alternative; right, Kepler, as in 1 year away. The GTX580 just got "Radeon-ed" in it's rear. I'm not biased towards either manufacturer, just love to see and give credit to a team of people with passion, vision, and hardwork come together and put their company back on the map, as is shown here today with AMD's launch of the 7970. It's AMD's version of "Tebow Time!!"


    Not at all, actually. It offers great gaming performance, and for everything else...we have to wait, because it's not fully baked yet. They say fools rush in. This thing launched today. We were given less than a week with it. It won't be available to even *buy* for another three weeks. Are you telling me you're ready to crown a paper winner, and you're not biased? Please...
  • 10 Hide
    Zombeeslayer143 , December 22, 2011 4:04 AM
    cangeliniHate to break it to you, but there won't be, unless you celebrate Christmas in mid-January.Start treating your SO super-nice and ask for one for Valentine's Day!


    Dude!!! I'm will be glued to NewEgg via my PDA and PC...I'm sooooo ooohhhh getting two of these!! If they sell for $549, I still think they provide the best value based on current high-end single GPU solutions (e.g., GTX 580, 6970, etc). Nvidia may want to consider a 20%-30% price reduction on the 580's once the 7970's are out.
  • -8 Hide
    Zombeeslayer143 , December 22, 2011 4:15 AM
    ZombeeSlayer143Dude!!! I'm will be glued to NewEgg via my PDA and PC...I'm sooooo ooohhhh getting two of these!! If they sell for $549, I still think they provide the best value based on current high-end single GPU solutions (e.g., GTX 580, 6970, etc). Nvidia may want to consider a 20%-30% price reduction on the 580's once the 7970's are out.


    You have a valid argument there. However, it's not like we need to wait for Windows 8 to see what this GPU is made of, as was the case with Bulldozer. What you see is what we will get give or take 5%?????? Heck, I don't even care for the overclocking potential. If the performance was capped at what is shown here today, I'm certain everyone will be happy. But, of course thats not the case, which brings me back to your point; it's too early, don't get excited, it's just on paper right? LOL...sure buddy...I'm so glad NewEgg was sold out of the GTX580 Classified's the past few weeks; would have regretted that purchase.
  • 6 Hide
    masterofevil22 , December 22, 2011 4:15 AM
    Ahhh....I'll be on the EGG myself and on E of Bay with my 6950 (unlocked) the day this beast this arrives!!!!!!! :D 

    WOW...Go ATI!!!!
  • 15 Hide
    jdwii , December 22, 2011 4:18 AM
    Well Amd you did it, Wow it's been a while since i was able to say that, I'm so impressed with these results everything you guys used to fail on you fixed at your GPU division. I'm not going to lie i did not think Amd would pay it off but they did. All i can say is Nice and well done. You guys beat Nvidia with a 28nnm gpu. I just wonder what's going on at nvidia and why their behind on the 28nm die, And their is rumors that Nvidia wont get their new card out until 2Q of 2012!!


    To bad these cards wont be out this year they would make a lot of money. Oh well parents usually buy them self stuff after christmas i guess.
  • 23 Hide
    aznshinobi , December 22, 2011 4:23 AM
    OMG DAT OVERCLOCKING!
    I can't wait to get the 7850 or 7870 and OC the crap out of it!
  • 10 Hide
    Zero_ , December 22, 2011 4:28 AM
    Overclocking like a baws! It DOES beat a GTX590!
  • 13 Hide
    bavman , December 22, 2011 4:42 AM
    Damn, I didn't see this coming from AMD. This card is a beast...it takes on multi-gpu cards...price is a little high, but compared to the performance it looks like an amazing value.
  • 19 Hide
    hardcore_gamer , December 22, 2011 4:48 AM
    I'm getting one of these for my <30nm build (28 nm GPU and 22nm CPU). I'm callin it the "MOORE'S AR$E"
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