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
Civilization V
Our final game, Civilization 5, gives us an interesting look at things that other RTSes cannot match, with a much weaker focus on shading in the game world, and a much greater focus on creating the geometry needed to bring such a world to life. In doing so it uses a slew of DirectX 11 technologies, including tessellation for said geometry, driver command lists for reducing CPU overhead, and compute shaders for on-the-fly texture decompression.
Because of the fact that Civilization V uses driver command lists, we were originally not going to include it in this benchmark suite as a gaming benchmark. If it were solely a DCL test it would do a good job highlighting the fact that AMD doesn’t currently support the feature, but a poor job of actually explaining any hardware/architectural differences. It was only after we saw AMD’s reviewer’s guide that we decided to go ahead and include it, because quite frankly we didn’t believe the numbers AMD had published.
With the GTX 580 and the 6970, the 6970 routinely lost to the GTX 580 by large margins. We had long assumed this was solely due to NVIDIA’s inclusion of DCLs, as we’ve seen a moderate single-GPU performance deficit and equally moderate multi-GPU lead for AMD melt away when NVIDIA added DCL support. The 7970 required that we rethink this.
If Civilization V was solely a DCL test, then our 2560 results would be impossible – the 7970 is winning by 12% in a game NVIDIA previous won by a massive margin. NVIDIA only regains their lead at 1680, which at this resolution we’re not nearly as likely to be GPU-bound.
So what changed? AMD has yet to spill the beans, but short of a secret DCL implementation for just CivV we have to look elsewhere. Next to DCL CivV’s other killer feature is its use of compute shaders, and GCN is a compute architecture. To that extent we believe at this point that while AMD is still facing some kind of DCL bottleneck, they have completely opened the floodgates on whatever compute shader bottleneck was standing in their way before. This is particularly evident when comparing the 7970 to the 6970, where the 7970 enjoys a consistent 62% performance advantage. It’s simply an incredible turnabout to see the 7970 do so well when the 6970 did so poorly.
Of course if this performance boost really was all about compute shaders, it raises a particularly exciting question: just how much higher could AMD go if they had DCLs? Hopefully one day that’s an answer we get to find out.
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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.