You know, we see 'enthusiast' performance in the graphics card vs gaming arena, but also 'extreme' performance. And to manage that we often produce articles where we take the best of the best in terms of performance, and then double, triple or quadruple it up thanks to multi-GPU performance.
If your wallet allows it, you can quite easily double up that GPU shader processor count and thus performance with the help of NVIDIA's SLI technology. Let's say that you pick two 479 EUR (499 USD) GeForce GTX 580 cards with 1.5 Gigs of memory each. Doubled up in SLI two of these puppies would bring seriously more performance to the table than a single 580, obviously.
Yes, Multi-GPU gaming has grown to become more popular over the past few year thanks to NVIDIA's SLI solutions initially, and obviously later on when ATI CrossfireX joined that path as well. So today we take two GeForce GTX 580 cards and place them into 2-way SLI mode. We'll throw in a combo Radeon cards setup in CrossfireX, both platforms armed with the very latest drivers, patches and games.
Over the next few pages we'll tell you a bit about multi-GPU gaming, the challenges, the requirements and of course a nice tasty benchmark session. We'll have a peek at temperatures, power consumption and we'll also overclock both GeForce GTX 580 cards in SLI mode to squeeze out every last ounce of performance.
Have a peek at the coolness in the photo below and then let's startup this article.
Explain that Multi-GPU mode you talk about...
Okay so we tend to get a little repetitive with this question, but honestly, is there anyone who visits this website that doesn't know what SLI & Crossfire is? Well surely the regulars know the idea and principles. But it never hurts to explain what we are dealing with today.
Both NVIDIA's SLI and AMD's ATI Crossfire allow you to combine/add a second or even third similar generation graphics card (or add in more GPUs) to the one you already have in your PC. This way you effectively try to double, triple or even quadruple your raw rendering gaming performance (in theory). The more GPUs, the worse the scaling becomes though, two GPUs in most scenarios, is ideal.
Think of a farmer with a plough and one horse. One horse will get the job done yet by adding a second or third horse, you'll plough through that farmland much quicker and (hopefully) more efficiently as the weight of that plough is distributed much more evenly. That's roughly the same idea for graphics cards. One card can do the job sufficiently, but with two or more you can achieve much more.
So along these lines, you could for example place two or more ATI graphics cards into a Crossfire compatible motherboard, or two or more NVIDIA GeForce graphics cards in SLI mode on a compatible motherboard.
A Crossfire compatible motherboard is pretty much ANY motherboard with multiple PCIe x16 slots that is not an nForce motherboard.
An SLI certified motherboard is an nForce motherboard with more than two PCIe x16 slots or a certified P55 or X58 motherboard. If your motherboard does not have the SLI certification mentioned on the box, it's likely not SLI compatible. Keep that in mind.
Once we seat the similar graphics cards on the carefully selected motherboard we just bridge them together, with a supplied Crossfire connector or in NVIDIA's case, an SLI connector. Then install/update the drivers, after which most games can take advantage of the extra horsepower we just added into the system.
Multi GPU rendering -- the idea is not new at all... if you are familiar with the hardware developments over the past couple of years you'll remember that 3dfx had a very familiar concept with the Voodoo 2 graphics cards series. There are multiple ways to manage two cards rendering one frame; think of Super tiling, it's a popular form of rendering. Alternate Frame Rendering, each card will render a frame (even/uneven) or Split Frame Rendering, simply one GPU renders the upper or the lower part of the frame.
So you see, there are many methods where two or more GPUs can be utilized to bring you a substantial gain in performance.
Alright, we've covered most of the hardware. We'll now have a peek at the configuration used, the hardware and software suite and then fire off the benchmarks in which we'll demonstrate the performance.
Final Words & Conclusion
In our previous multi-GPU articles we have already learned that NVIDIA graphics adapters obviously scale extremely well. This article is not different, with the one exception that we have so much graphics horsepower under the hood that we far more quickly run into a CPU bottleneck (the state where the GPUs are waiting on the CPU to provide data). Though that might seem bothersome, it really is luxury problem to have.
Performance wise, not a lot of negatives can be said about the GeForce GTX 580 setup in SLI. In previous articles we have shown you guys already that the performance scaling of two GPUs is something the GTX 400 and thus now 500 series as well, is really good at.
Heat and noise will definitely go up depending on your configuration, but remain acceptable. If you can please do place the cards as far away from each other as possible, a special flexible SLI bridge is required for that though.
Power consumption then, well it is high. When observing Crysis Warhead, which really is tremendously GPU intense, we notice power draws well over the 700+ Watt. You do need to be aware of that, each GPU has a 242W TDP, that's nearing 500 Watt already. Then add a nice spicy processor, likely overclocked a little drawing say 175W~200W and then the residuals like chipset and devices really can accumulate to significant numbers. But hey, this is the extreme high-end arena, it never has been any different. It's just that over the past years we as consumers and press have become much more critical about this topic.
We also really need to mention that one of the boards used (engineering sample) had an older BIOS and that power consumption on that board might be a tad higher as a result of it.
Now keep this in mind, with the more GPU stringent monitor resolutions and modern games you can gain 1.6x ~ 1.9x performance with two of these cards and that really is exemplary.
To be able to operate two or more cards in SLI mode you'll need an SLI certified motherboard. Most Intel X58 based motherboards are SLI certified, and often P55 motherboards as well. That or an older nForce motherboard (which is a dying breed). But carefully make sure and check that out before opting for SLI, okay ?
The big question remains, do you really need SLI with cards as powerful as the GeForce GTX 580 really is? Well, with current games and the brute force that is the GeForce GTX 580, one card will do more than fine of course. It's always like this though, that x-factor, going that extra mile, you gotza have a little more e-peen, you are a record breaker or simply want the best. If you fall within that category then this might be something you should opt.
There's of course another reason you might want to look into SLI, and this is a very valid point: If you like to opt triple screen gaming with NVIDIA's Surround vision option, you will need a serious amount of rendering performance. Add to that if you have beefed up your game platform with 3D Vision, well that's where this feature eats away hefty on your framerate budget, that's where an SLI setup like this actually makes a lot of sense. And for surround vision, SLI is actually a mandatory requirement.
Bare in mind, so much GPU horsepower needs a very spicy PC that can keep up with them GPUs. Also do the right thing and go for a Kilowatt PSU, have a little extra always ... at all times.
We certainly enjoyed testing these two cards in SLI. If you can live with the deficits like power consumption and the sheer amount of money needed to create your game PC that is. Yeah, it puts the full G in Geforce alright :)
We have not seen any driver issues, we did not run into any weird stuff and neither did we had to configure anything. Everything worked straight out of the box with near perfect scaling. As such if you are interested in marvelous game performance and are gaming with an unlimited budget, then this might be your route to follow.
No comments:
Post a Comment