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.
Facebook
Twitter
RSS
292 Comments
View All Comments
Scali - Monday, December 26, 2011 - link
Lol, how's that, when I'm the one saying that AMD's cards are the best performers in Crysis 2?I'm neutral, a concept that is obviously alien to you. Idiots...
Scali - Monday, December 26, 2011 - link
Heck, I'm also the guy who made Endless City run on non-nVidia cards. How does that make me an nVidia fanboy?CeriseCogburn - Thursday, March 8, 2012 - link
That's sad when an nvidia fanboy has to help all the amd fannies with software coding so they can run a benchmark, then after all that work to help the underprivileged, nothing but attacks after the facts... finally silence them.It's really sad when the truth is so far from the pop culture mind that actually speaking it is nearly forbidden.
Thank you for helping them with the benchmark. Continue to be kind in such ways to the sour whining and disgruntled, as it only helped prove how pathetic amd dx11 was...
james007 - Friday, December 30, 2011 - link
This sounded like such an awesome card and I was psyched to get it the moment it comes out -- until reading the part about dropping the 2nd DVI port. A DisplayPort-to-SLDVI doesn't do it, for me, because my desktop has to drive two 30" displays. In fact, I would love to be able to drive a third display so I can have a touch-screen also. My current (previous-generation) VDC does drive both displays just fine.This does not seem like such an infrequent requirement, especially for high-end users. Why would they drop the ability to drive the 2nd display? !!!
Argh!
The_Countess666 - Saturday, December 31, 2011 - link
not trying to sell you anything but, HDMI to dual-link dvi does exist (see link, or google yourself for other shops).http://sewelldirect.com/hdmi-to-dvi-dual-link-cabl...
and these cards do have 1 HDMI-out so that should work for you.
Penti - Wednesday, January 4, 2012 - link
It's the IHV that makes those decisions any way, just because it's not on a reference card doesn't mean they won't show up or that you can't build a card with it. But the HDMI supports more then 1920x1200 finally on this card any how. I guess they could deliver a card with the old type of DVI>HDMI adapters. Obviously opting for HDMI and multidisplaycapable displayport 1.2 makes more sense though. It's been around for years now.Penti - Wednesday, January 4, 2012 - link
Just make sure you actually has the number of connections you need when buying the card, many 7970 bords only appear to support single-link DVI on the DVI-connector.poordirtfarmer2 - Wednesday, January 4, 2012 - link
Enjoyed the article.So this new 79XX architecture is about a GPU architecture that’s also good for “compute work”. The reference to NVIDIA ‘s professional video cards (Quadro ; Telsa), implies to me that this might mean video cards viable for use both in gaming and in engineering / video work stations.
I’m not a pro, but do a lot of video editing, rendering and encoding. I’ve avoided dedicating a machine with an expensive special purpose QUADRO video card. Am I reading the wrong thing into this review, or might the new 79XX and the right driver give folks like me the best of both worlds?
radojko - Thursday, January 5, 2012 - link
UVD 3 in NextGen is a disappointing. Nvidia is two generation in front with PureVideo HD 5.psiboy - Monday, January 9, 2012 - link
Well Mr Ryan Smith I must ask why the omission of 1920 x 1080 in al lbenchmarks... given that almost every new monitor for quite some time has been natively 1920 x 1080... what is it with you guys and Tom's lately.. you both seem to have been ignoring the reality of what most of your readers are using!