NVIDIA GeForce GTX 460 SLI Performance Follow-up
Our first look at the GeForce GTX 460 showed it to be an impressive product with excellent all-around performance for the price. But what about SLI performance? How does GTX 460 SLI performance compare with a single GTX 480 or GTX 470 in real world gaming? Two 460 cards are now only $80 more than a single GTX 470.
GeForce GTX 460 SLI
After our first look at the GeForce GTX 460 went live this morning, a great deal of interest was expressed in our excellent forums regarding SLI performance of the new GPU. Of particular interest to our readers are comparisons to a single GeForce GTX 480, and a single GeForce GTX 470. We did not have enough time to include this in our initial evaluation, but due to demand we decided to roll on and provide some SLI performance evaluation pronto. These are a bit scaled down compared to our normal real world gaming tests, but we think we have what you are looking for.
These tests were performed on the same test system used for our GeForce GTX 460 evaluation.
We have decided to go ahead and use the newly released NVIDIA ForceWare drivers as of 7/12/2010. Our first evaluation used the ForceWare 258.80 Beta driver that NVIDIA made available for us during testing. This morning, NVIDIA made their ForceWare 258.96 WHQL-Candidate driver available for the GPU’s launch, so we used the new driver for these tests.
For the following apples-to-apples performance tests, we used a pair of GeForce GTX 460 1GB video cards in SLI, including one reference card from NVIDIA, and a non-standard design from Galaxy. The galaxy card has a high overclock out of the box, but both video cards were run at reference clock speeds for these tests, which is 675MHz core, 1350MHz shader and 3.6GHz memory. We used a standard-clocked GeForce GTX 480, and a standard-clocked GeForce GTX 470 in all of these tests.
GeForce GTX 460 SLI Performance Comparisons
In the interest of expediency, we have included three games from our testing suite. We are using Battlefield: Bad Company 2, Metro 2033, and Singularity.
Battlefield: Bad Company 2
For testing GTX 460 SLI performance in Battlefield: Bad Company 2, we configured the game to run at 2560x1600 with 4X MSAA, 16X AF, and the highest in-game settings available.
In BFBC2, the GeForce GTX 460 SLI setup enjoyed a 16% performance advantage over the single GeForce GTX 480, and a 35% advantage over the single GeForce GTX 470. While this configuration was playable on the GTX 460 SLI and the GTX 480, it was not playable on the GTX 470.
For Metro 2033, we configured the game to run in DirectX 11 at 2560x1600 with the "Very High" graphics option configured and AAA selected. We enabled Tessellation, but disabled Advanced DoF. With 4X MSAA enabled in this game, performance tanked on all three GPU configurations we selected, so we chose AAA instead.
For Metro 2033, the GTX 460 SLI configuration gave us 22% higher average framerate than the solo GTX 480. The GTX 470 did even worse, giving us framerates 38% slower than the GTX 460s in SLI. Here again, the GTX 460 SLI and GTTX 480 setups were playable in this configuration, while the GTX 470 was very slow and unpleasant.
For testing Singularity, we configured the game to run at 2560x1600 with 4X MSAA, 16X AF, and the highest in-game settings available. To enable AA functionality in this game, we selected the "Override" option in NVIDIA’s Control Panel and selected "4x" from the drop-down list.
In this game, we actually ran into a little snag. As you can see by the graph, the game stopped responding twice for about ten seconds when we were using our pair of GeForce GTX 460s in SLI. First, the game’s picture froze while the audio continued. After a few seconds, the screen went completely black. A few seconds later, it came back up and everything was just fine. This happened at seemingly random intervals every time we tested this game with the GTX 460s in SLI. It did not happen with a single GTX 460, nor did it happen with the GTX 480 or GTX 470. We also tested at 2X AA and still encountered the issue, so we do not think it is memory capacity issue but rather possibly a bug with SLI in this game.
Apart from that, everything was grand. Even with the dips into 0fps, the GTX 460 SLI setup gave us 10% higher framerates than the GTX 480, and 20% higher framerates than the GTX 470. Using this configuration, Singularity was playable on all three of these video card setups.
Raw performance numbers aside, there were some differences in the character of gameplay that I would like to address here. None of this is uncommon with SLI (or even CrossFireX), but I think it is worth repeating. Though the GTX 460 SLI setup gave us higher framerates across the board than the GTX 480, the GTX 480 in some places we experienced a more fluid gameplay quality. With SLI, there is a certain amount of overhead involved in managing the two video cards, dividing workload, and copying data between them. At the worst of times, this can result in diminished potential. It was most noticeable in Singularity, wherein there was noticeable input lag with the GTX 460 SLI setup. It wasn’t particularly severe, and it did not render that configuration unplayable, but it was there and you could "feel" it. Of course, Singularity had another performance anomaly as shown in our graph above, so it could be related. Metro 2033 and BFBC2 were affected somewhat as well, but it was less severe. Framerates are not the end all be all to performance when playing with SLI and CrossFireX, you truly have to pay attention to fluidity, responsiveness and consistency of the game as you play.
The Bottom Line
The GeForce GTX 460 is impressive from every angle. In addition to the accolades we heaped upon it in our first evaluation, we can now say that SLI performance is fantastic as well. Two GeForce GTX 460 1GB video cards with SLI enabled are significantly faster than one single GeForce GTX 480 and absolutely superior to one single GeForce GTX 470 in performance in real world gaming. No benchmarks! REAL GAMING turned in some amazing performance increases. The results were quite astonishing to us; we did not expect GTX 460 SLI to be that much faster when the canned benchmarks were put aside. It seems that NVIDIA’s SLI is extremely efficient and both GPUs are being utilized very well to improve performance.
This has the potential to help gamers create some seriously powerful gaming PCs from a cost limited perspective. Two 1GB GTX 460 video cards will cost you about as much as a single GTX 480, but if your budget requires that you upgrade or build your gaming machine in phases, the cost of a GTX 460 SLI setup can be spread over two purchases, unlike that of the GTX 480. The fact that you get superior performance to the GeForce GTX 480 for the same price makes GTX 460 1GB SLI a significant value for gaming.
Two GTX 460 1GB video cards with SLI enabled is a more appealing option than the GTX 480 when considering performance and price. However, that is where it ends with the GTX 460 1GB SLI configuration. A single GeForce GTX 480, while slower than GTX 460 SLI, has the ability to expand to two GTX 480’s with SLI enabled pushing performance well beyond that of the GTX 460 1GB SLI configuration. The GTX 460 SLI is also limited to two cards. So while GTX 460 1GB SLI is faster than GTX 480, it is at its limits and the GTX 480 does give you the option to expand along with a higher memory capacity footprint that has more benefits as NV Surround and 3D Vision come into play. It is however an interesting choice gamers now have and more options are certainly a good thing.
Importantly as well, the GTX 460 SLI supports NV Surround multi-display gaming while a single GTX 480 does not. A GTX 460 SLI configuration is going to be somewhat limited in NV Surround gaming due to its smaller memory footprint if you are one of those folks that must have high levels of AntiAliasing. But if you take a look at what you can accomplish with a aging GTX 280 SLI NV Surround configuration with also "only" 1GB of memory per GPU, it paints a very pretty picture as to what a huge amount of extra shader power could do for you in a GTX 460 SLI NV Surround setup. If you are looking at doing GTX 460 SLI we would highly suggest going with the 1GB memory card with the 256-bit memory bus. We don't think the wider bus makes that big of a difference, but when utilizing these larger resolutions, you will know that extra money was well spent on 1GB of RAM rather than 768MB. In our GTX 280 SLI NV Surround experience we saw many places where 768MB would have held us back.