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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Zingam - Thursday, December 22, 2011 - link
I think this card is a kinda fail. Well, maybe it is a driver issue and they'll up the performance 20-25% in the future but it is still not fast enough for such huge jump - 2 nodes down!!!It smell like a graphics Bulldozer for AMD. Good ideas on paper but in practice something doesn't work quite right. Raw performance is all that counts (of course raw performance/$).
If NVIDIA does better than usual this time. AMD might be in trouble. Well, will wait and see.
Hopefully they'll be able to release improved CPUs and GPUs soon because this generation does not seem to be very impressive.
I've expected at least triple performance over the previous generation. Maybe the drivers are not that well optimized yet. After all it is a huge architecture change.
I don't really care that much about that GPU generation but I'm worried that they won't be able to put something impressively new in the next generation of consoles. I really hope that we are not stuck with obsolete CPU/GPU combination for the next 7-8 years again.
Anyway: massively parallel computing sounds tasty!
B3an - Thursday, December 22, 2011 - link
You dont seem to understand that all them extra transistors are mostly there for computing. Thats mostly what this was designed for. Not specifically for gaming performance. Computing is where this card will offer massive increases over the previous AMD generation.Look at Nvidia's Fermi, that had way more transistors than the previous generation but wasn't that much faster than AMD's cards at the time. Because again all the extra transistors were mainly for computing.
And come on LOL, expecting over triple the performance?? That has never happened once with any GPU release.
SlyNine - Friday, December 23, 2011 - link
The 9700pro was up to 4x faster then the 4600 in certian situations. So yes it has happened.tzhu07 - Thursday, December 22, 2011 - link
LOL, triple the performance?Do you also have a standard of dating only Victoria's Secret models?
eanazag - Thursday, December 22, 2011 - link
I have a 3870 which I got in early 2007. It still does well for the main games I play: Dawn of War 2 and Starcraft 2 (25 fps has been fine for me here with settings mostly maxed). I have eyeing a new card. I like the power usage and thermals here. I am not spending $500+ though. I am thinking they are using that price to compensate for the mediocre yields they getting on 28nm, but either way the numbers look justified. I will be look for the best card between $150-$250, maybe $300. I am counting on this cards price coming down, but I doubt it will hit under $400-350 next year.No matter what this looks like a successful soft launch of a video card. For me, anything smokes what I have in performance but not so much on power usage. I'd really not mind the extra noise as the heat is better than my 3870.
I'm in the single card strategy camp.
Monitor is a single 42" 1920x1200 60 Hz.
Intel Core i5 760 at stock clocks. My first Intel since the P3 days.
Great article.
Death666Angel - Thursday, December 22, 2011 - link
Can someone explain the different heights in the die-size comparison picture? Does that reflect processing-changes? I'm lost. :D Otherwise, good review. I don't see the HD7970 in Bench, am I blind or is it just missing.Ryan Smith - Thursday, December 22, 2011 - link
The Y axis is the die size. The higher a GPU the bigger it is (relative to the other GPUs from that company).Death666Angel - Friday, December 23, 2011 - link
Thanks! I thought the actual sizes were the sizes and the y-axis meant something else. Makes sense though how you did it! :-)MonkeyPaw - Thursday, December 22, 2011 - link
As a former owner of the 3870, mine had the short-lived GDDR4. That old card has a place in my nerd heart, as it played Bioshock wonderfully.Peichen - Thursday, December 22, 2011 - link
The improvement is simply not as impressive as I was led to believed. Rumor has it that a single 7970 would have the power of a 6990. In fact, if you crunch the numbers, it would be at least 50% faster than 6970 which should put it close to 6990. (63.25% increase in transistors, 40.37% in TFLOP and 50% increase in memory bandwidth.)What we got is a Fermi 1st gen with the price to match. Remember, this is not a half-node improvement in manufacturing process, it is a full-node and we waited two years for this.
In any case, I am just ranting because I am waiting for something to replace my current card before GTA 5 came out. Nvidia's GK104 in Q1 2012 should be interesting. Rumored to be slightly faster than GTX 580 (slower than 7970) but much cheaper. We'll see.