AMD Radeon HD 7970 Review: 28nm And Graphics Core Next, Together As One
by Ryan Smith on December 22, 2011 12:00 AM EST- Posted in
- GPUs
- AMD
- Radeon
- ATI
- Radeon HD 7000
Portal 2
Portal 2 continues the long and proud tradition of Valve’s in-house Source engine. While Source continues to be a DX9 engine, Valve has continued to upgrade it over the years to improve its quality, and combined with their choice of style you’d have a hard time telling it’s over 7 years old at this point. Consequently Portal 2’s performance does get rather high on high-end cards, but we have ways of fixing that…
Given Portal 2’s wide range of performance it’s possible to at least somewhat bog it down on the GPU side without any special tricks thanks to its heavier use of shaders than in past Valve titles. Given a fast enough card I believe we could hit the 300fps internal Source framerate cap on our testbed, but thankfully at 2560 we’re nowhere close. In any case at 2560 the 7970 is well into the stratosphere, delivering 128.9fps, which is 18% better than the GTX 580. Meanwhile at 1920 as with so many other benchmarks that lead shrinks, this time down to 11%. Meanwhile the 7970 enjoys a smaller lead over the 6970, beating it by only around 30% at either resolution.
The great thing about the Source engine is that it’s well studied, and by utilizing DirectX9 it’s open to a few more image quality enhancements than DX10+ games. We’ve always wanted to have a standard benchmark with more anti-aliasing than just MSAA, and Portal is the perfect candidate. So for the second part of this test, we’ve turned on Super Sample Anti-Aliasing (SSAA) through NVIDIA and AMD’s driver control panels. With SSAA the entire scene gets anti-aliased, going beyond just removing the jaggies at polygon edges and removing all signs of shader aliasing too, making Portal 2 a very good looking game.
As expected, SSAA makes the performance of everything tank. At 2560 the 7970 is well below 60fps, and every other single-GPU card is slower yet. Once we get down to 1920 performance finally reaches a point where it’s playable, as the 7970 reaches 72.2fps.
Compared to its competition, it’s interesting to note that we appear to have hit an entirely different set of bottlenecks by using SSAA. The 7970 leads the GTX 580 by 9% at both resolutions while it leads the 6970 by 25% under the same conditions. We believe that at this point we’re seeing the limitations of ROP performance, which would explain why the 7970’s lead diminishes versus both the GTX 580 and 6970. The additional bandwidth the 7970’s design affords the ROPs can only go so far until it once again becomes a matter of pixel pushing power.
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Scali - Saturday, December 24, 2011 - link
I have never heard Jen-Hsun call the mock-up a working board.They DID however have working boards on which they demonstrated the tech-demos.
Stop trying to make something out of nothing.
Scali - Saturday, December 24, 2011 - link
Actually, since Crysis 2 does not 'tessellate the crap' out of things (unless your definition of that is: "Doesn't run on underperforming tessellation hardware"), the 7970 is actually the fastest card in Crysis 2.Did you even bother to read some other reviews? Many of them tested Crysis 2, you know. Tomshardware for example.
If you try to make smart fanboy remarks, at least make sure they're smart first.
Scali - Saturday, December 24, 2011 - link
But I know... being a fanboy must be really hard these days..One moment you have to spread nonsense about how Crysis 2's tessellation is totally over-the-top...
The next moment, AMD comes out with a card that has enough of a boost in performance that it comes out on top in Crysis 2 again... So you have to get all up to date with the latest nonsense again.
Now you know what the AMD PR department feels like... they went from "Tessellation good" to "Tessellation bad" as well, and have to move back again now...
That is, they would, if they weren't all fired by the new management.
formulav8 - Tuesday, February 21, 2012 - link
Your worse than anything he said. Grow upCeriseCogburn - Sunday, March 11, 2012 - link
He's exactly correct. I quite understand for amd fanboys that's forbidden, one must tow the stupid crybaby line and never deviate to the truth.crazzyeddie - Sunday, December 25, 2011 - link
Page 4:" Traditionally the ROPs, L2 cache, and memory controllers have all been tightly integrated as ROP operations are extremely bandwidth intensive, making this a very design for AMD to use. "
Scali - Monday, December 26, 2011 - link
Ofcourse it isn't. More polygons is better. Pixar subdivides everything on screen to sub-pixel level.That's where games are headed as well, that's progress.
Only fanboys like you cry about it.... even after AMD starts winning the benchmarks (which would prove that Crysis is not doing THAT much tessellation, both nVidia and new AMD hardware can deal with it adequately).
Wierdo - Monday, January 2, 2012 - link
http://techreport.com/articles.x/21404"Crytek's decision to deploy gratuitous amounts of tessellation in places where it doesn't make sense is frustrating, because they're essentially wasting GPU power—and they're doing so in a high-profile game that we'd hoped would be a killer showcase for the benefits of DirectX 11
...
But the strange inefficiencies create problems. Why are largely flat surfaces, such as that Jersey barrier, subdivided into so many thousands of polygons, with no apparent visual benefit? Why does tessellated water roil constantly beneath the dry streets of the city, invisible to all?
...
One potential answer is developer laziness or lack of time
...
so they can understand why Crysis 2 may not be the most reliable indicator of comparative GPU performance"
I'll take the word of professional reviewers.
CeriseCogburn - Sunday, March 11, 2012 - link
Give them a month or two to adjust their amd epic fail whining blame shift.When it occurs to them that amd is actually delivering some dx11 performance for the 1st time, they'll shift to something else they whine about and blame on nvidia.
The big green MAN is always keeping them down.
Scali - Monday, December 26, 2011 - link
Wrong, they showed plenty of demos at the introduction. Else the introduction would just be Jen-Hsun holding up the mock card, and nothing else... which was clearly not the case.They demo'ed Endless City, among other things. Which could not have run on anything other than real Fermi chips.
And yea, I'm really going to go to SemiAccurate to get reliable information!