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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mak360 - Monday, March 5, 2012 - link
Enjoy, now go and buyImSpartacus - Monday, March 5, 2012 - link
Yeah, I'm trying to figure out if a 7850 could go in an Alienware X51. It looks like it uses a 6 pin power connector and puts out 150W of heat.While we would lose Optimus, would it work?
taltamir - Monday, March 5, 2012 - link
optimus is laptops only. You do not have optimus with your desktop.ImSpartacus - Monday, March 5, 2012 - link
The X51 has desktop Optimus."The icing on the graphics cake is that the X51 is the first instance of desktop Optimus we've seen. That's right: you can actually plug your monitor into the IGP's HDMI port and the tower will power down the GPU when it's not in use. This implementation functions just like the notebook version does, and it's a welcome addition."
http://www.anandtech.com/show/5543/alienware-x51-t...
In reality, if I owned an X51, I would wait so I could shove the biggest 150W Kepler GPU in there for some real gaming.
But I'm sure the X51 will be updated for Kepler and Ivy Bridge, so now wouldn't be the best time to get an X51.
Waiting games are lame...
scook9 - Monday, March 5, 2012 - link
Wrong. Read a review.....The bigger issue will be the orientation of the PCIe Power Connector I expect. I have a tightly spaced HTPC that currently uses a GTX 570 HD from EVGA because it was the best card I could fit in the Antec Fusion enclosure. If the PCIe power plugs were facing out the side of the card and not the back I would have not been able to use it. I expect the same consideration will apply to the even smaller X51kungfujedis - Monday, March 5, 2012 - link
he does. x51 is a desktop with optimus.http://www.theverge.com/2012/2/3/2768359/alienware...
Samus - Monday, March 5, 2012 - link
EA really screwed AMD over with Battlefield 3. There's basically no reason to consider a Radeon card if you plan on heavily playing BF3, especially since most other games like Skyrim, Star Wars, Rage, etc, all run excellent on any $200+ card, with anything $300+ being simply overkill.The obvious best card for Battlefield 3 is a Geforce GTX 560 TI 448 Cores for $250-$280, basically identical in performance to the GTX570 in BF3. Even those on a budget would be better served with a low-end GTX560 series card unless you run resolutions above 1920x1200.
If I were AMD, I'd concentrate on increasing Battlefield 3 performance with driver tweaks, because it's obvious their architecture is superior to nVidia's, but these 'exclusive' titles are tainted.
kn00tcn - Monday, March 5, 2012 - link
screwed how? only the 7850 is slightly lagging behind, & historically BC2 was consistently a little faster on nvalso BF3 has a large consistent boost since feb14 drivers (there was another boost sometime in december, benchmark3d should have the info for both)
chizow - Tuesday, March 6, 2012 - link
@ SamusBF3 isn't an Nvidia "exclusive", they made sure to remain vendor agnostic and participate in both IHV's vendor programs. No pointing the finger and crying foul on this game, it just runs better on Nvidia hardware but I do agree it should be running better than it does on this new gen of AMD hardware.
http://www.amd4u.com/freebattlefield3/
http://sites.amd.com/us/game/games/Pages/battlefie...
CeriseCogburn - Monday, March 26, 2012 - link
In the reviews here SHOGUN 2 total war is said to be the very hardest on hardware, and Nvidia wins that - all the way to the top.--
So on the most difficult game, Nvidia wins.
Certainly other factors are at play on these amd favored games like C1 and M2033 and other amd optimized games.
--
Once again, on the MOST DIFFICULT to render Nvidia has won.