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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Ryan Smith - Monday, March 5, 2012 - link
Whoops, flipped a number. Thanks!Dark_Archonis - Monday, March 5, 2012 - link
Good to see AMD providing tough competition for Nvidia.Now, when do we see Kepler? Nvidia has been taking their sweet ass time with Kepler, it's frustrating. Fermi overall is a frustrating architecture, in that it's only fast in mid-high and high-end specifications. In mid-range and low-end cards Fermi sucks, when compared to equivalent AMD cards.
Well AT, how long do we have to wait for Kepler? I hope Kepler brings a big performance boost across the board for Nvidia. Intel will only keep improving their integrated graphics, so Nvidia's low and mid-range graphics offerings need to be MUCH better than they currently are, to be worth buying in the future. This is especially true in the laptop market.
Radnor - Monday, March 5, 2012 - link
Really for the exception of 7750 witch has a really low power draw, my i will stick with my 4850 CF for now. No reason for upgrade. I mean no new demanding games and 7xxxx ati cards are just expensive.Death666Angel - Monday, March 5, 2012 - link
"Once again the 7970 and 7950 place quite close to each other, particularly at 1920. "I think you mean 7870 and 7950? :-)
tech6 - Monday, March 5, 2012 - link
For those waiting for nVidea to come to the rescue with an amazing next generation product, I would urge you not to get your hopes up. Nvidea sees their future in the mobile space creating Tegra APUs and mobile graphics and this is where they are spending their R&D budget. The desktop graphics market is simply not growing much anymore.DeViLzzz - Monday, March 5, 2012 - link
some people care about Physx so we have to wait on Nvidia lolA5 - Monday, March 5, 2012 - link
Why? There's like 2 games that use it.CeriseCogburn - Thursday, March 8, 2012 - link
There's actually like 2 hundred, but keep drinking the radeonaide.SpaceRanger - Monday, March 5, 2012 - link
The lacking of WHQL Drivers has me shaking my head. Come on AMD. It's been 3 months and you STILL can't get a WHQL driver out for the 7xxx series!
DeViLzzz - Monday, March 5, 2012 - link
if you already have a 560 Ti I guess you hope for another price drop on the cards so you can SLI themif you can get your hands on an affordable used 6970 or a new Power Color 2 GB 6950 and flash it to a 6970 then do so