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- Date:
- Tuesday , January 11, 2011
- Author:
- Brent Justice
- Editor:
- Kyle Bennett
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AMD 6970/6950 CFX and NVIDIA 580/570 SLI Review
Ever wondered how the new Radeon HD 6970, Radeon HD 6950, GeForce GTX 580 and GeForce GTX 570 perform when paired up with a second card? We did, and we have evaluated all four combinations in AMD Eyefinity and NV Surround resolutions.
Performance Summary
Looking back at all our results, we come away with very mixed outcomes. There are some patterns that we see though, and it is these patterns that we need to flesh out. Fist let’s quickly recap what we saw in our gameplay experiences here, and then we will talk about the patterns that we have discovered in our experiences.
In F1 2010 we found that the AMD Radeon HD 6970 CrossFireX and Radeon HD 6950 CrossFireX configurations delivered the best gameplay experience. We were able to run at 8X MSAA at 5760x1200 delivering an impressive visual experience. The GeForce GTX 580 SLI was playable at 4X AA, bottlenecking at 8X MSAA, and the GTX 570 was only playable at 5040x1050 with No AA due to bottlenecks in this game.
Civilization V turned the tables and clearly favored the NVIDIA video cards. We were able to run at 4X AA at 5760x1200 on GTX 580 SLI while Radeon HD 6970 CrossFireX was playable with No AA at 5760x1200. GeForce GTX 570 SLI seemed to match the Radeon HD 6970 CrossFireX in this game while Radeon HD 6950 CrossFireX had to be lowered to 5040x1050 in order to be playable.
Metro 2033 showed a much more even playing field than the previous two games. Both the GeForce GTX 580 SLI and Radeon HD 6970 CrossFireX configurations were playable at 5760x1200 with "Very High" quality settings. In return, the GeForce GTX 570 SLI and Radeon HD 6950 CrossFireX were playable at the "High" quality setting. Only the GTX 580 SLI, 6970 CrossFireX and 6950 CrossFireX were able to play at 5040x1050 at "Very High" with 4X MSAA enabled.
Battlefield: Bad Company 2 highly favored the GeForce GTX 580 SLI configuration. We were able to run at 16X CSAA with 2X Transparency AA at 5760x1200 with room to spare. The Radeon HD 6970 CrossFireX was playable at 4X AA while Radeon HD 6950 CrossFireX was playable at 2X AA. The GeForce GTX 570 SLI seemed to match the experience of the Radeon HD 6970 CrossFireX.
Mafia II was experienced the best with the GeForce GTX 580. The GeForce GTX 580 was able to run the shader based AA plus enable the High Apex Physics. GeForce GTX 570 SLI was almost the same, but the PhysX had to be lowered to Medium. Both Radeon video cards were playable at their highest settings.
Memory Patterns
We brought up the differences in memory capacities in the introduction for a specific reason, because we saw some of that bottlenecking take place in our testing, but not always. It is rather intriguing how one game can be bottlenecked by memory capacity, but another not. In the cases were memory was not the bottleneck it seems one pattern we found emerge is that the GeForce GTX 580 SLI pulls well ahead of Radeon HD 6970 CrossFireX performance, which we think was expected.
Some of the situations where we were seeing memory capacity bottlenecks were in F1 2010 in the case of the GTX 580 and GTX 570 SLI. Our gameplay testing and our apples-to-apples testing showed that the GTX 580 SLI was not playable at 8X MSAA at 5760x1200, but by dropping it to 4X AA it received a massive performance boost and was playable. The GTX 570 SLI followed the same pattern. F1 2010 seems to be sensitive to memory capacity, and running at 5760x1200 with 8X MSAA is a heavy burden to bare. Both AMD video cards have 2GB of memory per GPU, and both GPUs were more than playable at 8X MSAA with faster performance.
In the case where memory capacity isn’t the bottleneck, we, at times, saw the GTX 580 SLI and even the GTX 570 SLI fly past the competition. Civilization V is one such game that we thought would be affected by memory capacity, but was not. We were actually able to run at a higher AA setting in this game with the video card combination that had less memory capacity. We were able to run at 4X AA at 5760x1200 on GTX 580 SLI which has less memory than the Radeon video cards. Now, it has to be said that this game has a history of performing better on NVIDIA GPUs when making comparisons at similar price points. For whatever reason, The GeForce GTX 580 and GTX 580 are just faster at accelerating this game.
Another two cases where the above pattern emerges is Battlefield: Bad Company 2 and Mafia II. In these two games, it seems the GTX 580 has just enough memory to allow very high settings, and performance outpaces the Radeon video cards. However, the GTX 570 did have problems running 8X MSAA in BC2 at 5760x1200, indicating its memory capacity was in fact a bottleneck.
When we look at how memory capacity affects performance, or the ability to use higher resolutions and AA settings the general rule still stands. You will want a video card with the most amount of memory on board to fully utilize a multi-GPU configuration at high resolutions with Antialiasing. It is simply science, and the nature of current multi-GPU acceleration technology. The more memory you have, the better scaling you will see and the better ability to actually use high settings at high resolutions. The Radeon HD 6970 and Radeon HD 6950 have 2GB of RAM per GPU, and on the whole, this provided benefit and resulted in no situation in which memory capacity was the bottleneck on both GPUs. Performance of the GPUs though is a different factor altogether, and our results indicate that it is mostly dependent on the game.
The Bottom Line
It all comes down to pricing, and a pair of GeForce GTX 580 cards is going to cost you over $1000 right now. That is a lot of money. It is a significant cost for gaming performance for most people. While it seems that speaking in GPU performance dual-GTX 580 GPUs are faster than dual-Radeon HD 6970 GPUs, the fact is they do have less memory capacity. For a higher price, you are getting less of a chance to actually use those higher settings. For all that performance the GTX 580 has, it could be held back in a multi-GPU configuration because of its memory capacity. And one thing all us multi-display gamers know is that AA becomes a lot more valuable as you scale resolutions to larger amounts of pixel real estate.
The GTX 580 price almost doesn’t seem worth it when you consider a pair of Radeon HD 6970 video cards will cost you $698, saving you a whopping $300. For that price savings you get more memory, which has the chance to allow higher playable settings, and performance that at times beats GTX 580 SLI and at other times cuts in under it, depending on the game.
The GeForce GTX 570 SLI is in an even worse position, its raw GPU performance is great, and it has good SLI scaling. However, it is severely held back by its memory capacity. We experienced many times that we could not use higher settings, or had to lower the resolution, because of that. The performance is there, but the ability to utilize that performance is not. Since a pair of GeForce GTX 570 video cards will run you $698, the same price as two Radeon HD 6970 video cards, it just isn’t worth it. For the same price as two GTX 570 cards you can get two Radeon HD 6970 video cards with a much higher memory capacity, and better performance. Even a pair of Radeon HD 6950 video cards becomes appealing when you look at its low price of $598 (or $558 after rebate) for two cards, which will save you another $100+ and still provide more memory and a good gameplay experience in AMD Eyefinity.
You just can’t beat the low prices AMD has set on the Radeon HD 6950 and Radeon HD 6970. Where the last generation of AMD GPU was neutered when it came to CrossFireX scaling, the 6970 and 6950 are "fixed" in that regard.
When running a multi-GPU configuration, memory capacity does matter at Eyefinity resolutions, and these video cards can be had cheaper than the competition. If you flat out want the highest raw performance, we have to say that is the GeForce GTX 580 SLI, depending on the game, but its memory capacity may hold you back if you are running NV Surround. For the best value, it is clearly the Radeon HD 6950 and Radeon HD 6970 CrossFireX setups. That is quite a change from the song we sang a few short months ago when the 5870 CrossFireX was destroyed by GTX 480 SLI.
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