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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SlyNine - Friday, December 23, 2011 - link
Are you nuts, the 5870 was nearly 2x as fast in DX 10/9 stuff, not to mention DX11 was way ahead of DX10. Sure the 6970 isn't a great upgrade from a 5870, but neither is the 7970.Questionable Premise
CeriseCogburn - Thursday, March 8, 2012 - link
That happened at the end of 2006 with the G80 Roald. That means AMD and their ATI Radeon aquisition crew are five years plus late to the party.FIVE YEARS LATE.
It's nice to know that what Nvidia did years ago and recently as well is now supported by more people as amd copycats the true leader.
Good deal.
Hauk - Thursday, December 22, 2011 - link
A stunningly comprehensive analysis of this new architecture. This is what sets Anandtech apart from its competition. Kudos Ryan, this is one of your best..eastyy - Thursday, December 22, 2011 - link
its funny though when it comes to new hardware you read these complicated technical jargon and lots of detailed specs about how cards do things different how much more technically complicated and in the end for me all it means is...+15fps and thats about itas soon as a card comes out for say 150 and the games i play become slow and jerky on my 460 then i will upgrade
Mockingbird - Thursday, December 22, 2011 - link
I'd like to see some benchmarks on FX-8150 based system (990fx)piroroadkill - Friday, December 23, 2011 - link
Haha, the irony is that AMD is putting out graphics cards that would be bottlenecked HARDCORE by ANY of their CPUs, overclocked as much as you like.It's kind of tragic...
Pantsu - Friday, December 23, 2011 - link
The performance increase was as expected, at least for me, certainly not for all those who thought this would double performance. Considering AMD had a 389mm^2 chip with Cayman, they weren't going to double the transistor count again. That would've meant the next gen after this would be Nvidia class huge ass chip. So 64% more transistors on a 365mm^2 chip. Looks like transistor density increase took a bit of a hit on 28nm, perhaps because of 384-bit bus? Still I think AMD is doing better than Nvidia when it comes to density.As far as the chip size is concerned, the performance is OK, but I really question whether 32 ROPs is enough on this design. Fermi has 48 ROPs and about a billion transistors less. I think AMD is losing AA performance due to such a skimpy ROP count.
Overall the card is good regardless, but the pricing is indeed steep. I'm sure people will buy it nonetheless, but as a 365mm^2 chip with 3GB GDDR5 I feel like it should be 100$ cheaper than what it is now. I blame lack of competition. It's Nvidia's time to drop the prices. GTX 580 is simply not worth that much compared to what 6950/560Ti are going for these days. And in turn that should drop 7970/50 price.
nadavvadan - Friday, December 23, 2011 - link
Am I really tired, or is:" 3.79TFLOPs, while its FP64 performance is ¼ that at 947MFLOPs"
supposed to be:
" 3.79TFLOPs, while its FP64 performance is ¼ that at 947-G-FLOPs"?
Enjoyed the review as always.
Death666Angel - Friday, December 23, 2011 - link
Now that you have changed the benchmark, would it be possible to publish a .pdf with the relevant settings of each game? I would be very interested to replicate some of the tests with my home system to better compare some results. If it is not too much work that is (and others are interested in this as well). :Dmarc1000 - Friday, December 23, 2011 - link
What about juniper? Could it make it's way to the 7000 series as a 7670 card? Of course, upgraded to GCN, but with same specs as current cards. I guess that at 28nm it would be possible to abandon the pci-e power requirement, making it the go-to card for oem's and low power/noise systems.I would not buy it because I own one now, but I'm looking forward to 7770 or 7870 and their nvidia equivalent. It looks like next year will be a great time to upgrade for who is in the middle cards market.