AMD Radeon HD 7870 GHz Edition & Radeon HD 7850 Review: Rounding Out Southern Islands
by Ryan Smith on March 5, 2012 12:01 AM ESTTheoretical Performance
Before moving on from compute performance, we wanted to quickly take a look at theoretical performance. This will be particularly helpful for highlighting the importance of core clockspeeds in AMD's GCN architecture.
We’ll start with a quick look at tessellation performance with the DX11 Detail Tessellation sample program. Because the 7900 series and the 7800 series share a common dual geometry engine frontend, geometry performance is almost entirely dictated by the core clock. As a result the 7870 and its 1GHz core clock just edges out the 7950 and its 800MHz core clock when it comes to tessellation performance. The rest of the difference comes down to shaders, where the 7950 has more shader resources to throw at the hull and domain shading parts of the tessellation process.
Of course that tessellation performance lead doesn’t always translate into great performance in tessellation heavy benchmarks. Unigine Heaven, in spite of its heavy use of tessellation still has the 7950 well ahead.
Finally, a quick look at 3DMark Vantage theoretical performance largely confirms what we’ve already seen. Pixel fill is heavily bandwidth limited, leading to the 7950 taking a large lead and even the 6970 edging out the 7800 series, though you’d never know it from the gaming benchmarks. Otherwise when it comes to texture fillrate, the 6970 and 7870 are in a dead heat.
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Taft12 - Monday, March 5, 2012 - link
Or don't. It's not on sale for 2 weeks yet.MySchizoBuddy - Monday, March 5, 2012 - link
NOT with 1/16 the FP64 performance.Zoomer - Wednesday, March 7, 2012 - link
FP64 is useless for games for the foreseeable future.CeriseCogburn - Thursday, March 8, 2012 - link
I love the "further image quality improvements page" which delicately and carefully explains how amd did a wonderful job of making things better as the image quality degrades...After noting the degredation very, very lightly and tossing out the problem, it is declared "unnoticable" for "all intents and purposes".
Eventually amd's IQ is going to be so far behind nvidia's the endless denials and it doesn't matters - will just continue since amd can crank an extra 20 fps doing it...
LOL
A "gift" from amd.
MySchizoBuddy - Monday, March 5, 2012 - link
where is the double precision compute benchmarksCeriseCogburn - Friday, March 9, 2012 - link
Article: " As AMD began winding down Cayman (6900 series) almost immediately with the launch of the 7900 series, at this point the 6900 market has effectively dried up. Having taken themselves out of competition with themselves, AMD’s only competition is NVIDIA’s lineup."--
And there we have it - AMD and their evil plot to squeeze every last dollar out of those "they care about", the gamers...
I don't want to hear Nvidia is evil anymore.
Time to look in the mirror amd users.
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Furthermore, it's time the reviewers start slamming AMD the way they slam Nvidia, in this case, one can consider it PRAISE for AMD "drying up their own card channels"- and if that isn't bias I don't know what is.
dagamer34 - Monday, March 5, 2012 - link
These cards don't seem like such a wonderful value considering what the 6900 series was offering, but since those cards have gone poof, I guess you'll have to settle for the 7800 series? It really just seems like they are adjusting their pricing scheme to be less compressed than it was before.TL: DR; If you've got a 6900 series card, the 7000 series is not for you.
Jedi2155 - Monday, March 5, 2012 - link
I still have my wonderful 5870 I purchased in 2009 (which now is not far from 3 years ago...), and still waiting for something that offers more performance than the 7970. Com'on Nvidia! Blow everything out of the water please....Death666Angel - Monday, March 5, 2012 - link
"TL: DR; If you've got a 6900 series card, the 7000 series is not for you."I'd say the 30 to 50% increase of the 79xx to 69xx cards could be well worth it. However, unless you run a multi-monitor setup or have a 2560 resolution, you really should think twice about spending that amount of money on these cards. But I guess people with that kind of cash can either do their own thinking or don't have to care too much about spending and can afford to "BUY ALL THE CARDS".
I'm still running a HD5770 and have a newly acquired 27" monitor here that is really stressing it. I think I'll go for a 78xx and later upgrade to CF because my 550W PSU can handle it with these cards, whereas HD69xx would be stressing it too much. :-)
cactusdog - Monday, March 5, 2012 - link
"TL: DR; If you've got a 6900 series card, the 7000 series is not for you."Thats the dumbest statement I have ever read here. The 7970 is DOUBLE the performance of the 6970 with overclocking. Even the $250 7850 beats the 6970 with overclocking.
The 7 series is the biggest performance jump over the previous series since I have followed graphics cards, since 1998.