AMD Radeon HD 7870 GHz Edition & Radeon HD 7850 Review: Rounding Out Southern Islands
by Ryan Smith on March 5, 2012 12:01 AM ESTCompute Performance
Moving on from our look at gaming performance, we have our customary look at compute performance. With GCN AMD significantly overhauled their architecture in order to improve compute performance, as their long-run initiatives rely on GPU compute performance becoming far more important than it is today.
Our first compute benchmark comes from Civilization V, which uses DirectCompute to decompress textures on the fly. Civ V includes a sub-benchmark that exclusively tests the speed of their texture decompression algorithm by repeatedly decompressing the textures required for one of the game’s leader scenes. Note that this is a DX11 DirectCompute benchmark.
The Civ V compute shader benchmark once again shows off just how much the compute shader performance of the 7800 series has improved relative to the 6900 series, with both 7800 cards coming in well, well ahead of any previous generation AMD cards. Compared to NVIDIA’s lineup the 7800 series does fairly well for itself too, although not quite as well as the commanding lead the 7900 series took.
Our next benchmark is SmallLuxGPU, the GPU ray tracing branch of the open source LuxRender renderer. We’re now using a development build from the version 2.0 branch, and we’ve moved on to a more complex scene that hopefully will provide a greater challenge to our GPUs.
SmallLuxGPU continues to showcase the 7800 series’ improvements over past AMD architectures, and while it’s not the same kind of massive leap we saw with CivV, it’s still enough to bring the 7850 up to near the performance of the 6970, and pushing the 7870 well beyond that. The only real competition here for AMD is AMD.
For our next benchmark we’re looking at AESEncryptDecrypt, an OpenCL AES encryption routine that AES encrypts/decrypts an 8K x 8K pixel square image file. The results of this benchmark are the average time to encrypt the image over a number of iterations of the AES cypher.
On the one hand, the 7870 gets quite close to the 7950 here in our AESEncryptDecrypt benchmark, in spite of the latter’s higher number of shaders. On the other hand, it’s still not enough to dethrone the GTX 570; the only NVIDIA cards the 7800 series can beat start at the GTX 560 Ti.
Finally, our last benchmark is once again looking at compute shader performance, this time through the Fluid simulation sample in the DirectX SDK. This program simulates the motion and interactions of a 16k particle fluid using a compute shader, with a choice of several different algorithms. In this case we’re using an (O)n^2 nearest neighbor method that is optimized by using shared memory to cache data.
In our final compute test the 7800 series once again makes a run at the top, with both cards rising past the GTX 570, although they can’t quite match the GTX 580. In an interesting turn of events the 7870 ends up being some 6% faster than the 7950, in spite of the fact that in a compute benchmark the 7950 should have a solid lead. This just goes to show that core clockspeeds do matter, and that adding more shaders alone can’t conquer all benchmarks.
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Beenthere - Tuesday, March 6, 2012 - link
Yes at the moment AMD is most definitely getting top dollar for these Vid cards just as Intel does all of the time on their CPUs - until they have competition.In case you didn't notice the new 7xxx series cards surpass Nvidia's current offerings in just about every category so this IS a step forward in performance at the same or lower prices.
MMoudry - Tuesday, March 6, 2012 - link
Hello,Does anybody know if those two cards would work in crossfire? The Crossfire compatibility chat is not yet up to date and I can't seem to find that information anywhere....
Sources:
http://sites.amd.com/us/game/technology/Pages/cros...
MM
Hrel - Tuesday, March 6, 2012 - link
Hd6870 and gtx 560 can be had for 160 and 165 respectively. WHY would anyone want the SIGNIFICANTLY slower 7770? It's not like it's directX 12 or something.Alpert - Tuesday, March 6, 2012 - link
I can understand why so many get it wrong but I can also clearly see.7770 currently retails for $169.99 - $179.99
6870's currently retail for $189.99 - $209.99 original price was $249.99
I just checked these numbers from 3 retailer
7770 is a weaker card then the 6870, sure but performance per dollar is actually a little better with the 7770. Considering the lack of competition from Nvidia why would AMD reduce the price to performance ratio that exists. AMD is selling you more features for a better value card.
When Kepler arrives AMD price's could go down if Nvidia prices it that way. If Kepler is all the #$%^ it's hyped to be AMD will counter it with a price drop then we all win. Looking at ATI/AMD's history something they have always offered the customer, superior price/performance of the competition.
AMD will always be better price to performance for less while Nvidia justifies there inflated prices with CUDA, PhysX, TWIMTBP and of course better driver support.
The value of performance will remain as is. Like a commodity on the stock exchange, why would Nvidia devalue there own stock or at least so quickly?
Hrel - Wednesday, March 7, 2012 - link
I checked the prices I listed on newegg just before posting that. Not sure where you got your prices from, but shop newegg in the future... that way you aren't wrong :p.bozolino - Tuesday, March 6, 2012 - link
There is something REALLY odd about 560 TI numbers on ELDERS SCROLL V.Under 7770 REVIEW it shows 7770 right above 550 TI and on the top of all them is a standard GTX 560 with like 46 fps and here, on this review it shows the GTX 560 TI with like 36 fps. The settings look just like the same..
Please correct that because it is looking like the GTX 560 TI is worse than the 7770, wich it isnt by at least a mile.
Alpert - Tuesday, March 6, 2012 - link
With a 7770 the power consumption is below that of the Radeon HD 6870 and GeForce GTX 560 Ti, while still delivering the same gameplay experience of those video cards. About 2%-7% slower then 560 Ti.CeriseCogburn - Thursday, March 8, 2012 - link
This isn't HardOCP Alpert.slypher1024 - Wednesday, March 7, 2012 - link
My 5850 still server me well @ 1600x900 res.. Not until these prices drop i'll upgrade..AMD is obviously maximizing profit with these products, seeing that Nvidia next launch is at least 2 months away...
SAD
gammaray - Wednesday, March 7, 2012 - link
Price wars, really?seriously, 250$ for a low end video card and 350$ for a mid range video card, not even the MAIN LINE serie but somewhat weaker versions of their 7900 serie counterpart.
Video card markets have been ripping off consumers in the past years with their super hefty high prices.
it should be like that: 150$ for new low end video cards, 250$ for new mid-range and 350$+ for whatever they want to sell to whoever will always buy the most expensive stuff no matter.
the price of the 6800 should all be below 100$ right now and the 6900 serie prices cut in half .