Summary: When 2 GeForce 8800 Ultras isn't enough for Crysis, what is a gamer to do? Why not try 3 GeForce 8800 Ultras! That's what today's 3-Way SLI launch is all about -- more performance. See how the platform stacks up in this article!
Ultimately there were only a handful of cases were the technology really showed its full potential.
NVIDIA eventually ironed these issues out with the debut of their second generation Quad SLI card, the GeForce 7950 GX2, but these cards were extremely expensive and due to limitations within DirectX 9, the 7950 GX2 didn’t always offer true 4-way AFR scaling in Direct3D games. In order for the GeForce 7950 GX2 Quad SLI to truly shine, you had to crank up the AA to 8x. Here the GeForce 7950 GX2 Quad SLI platform really began to pull away from more conventional SLI setups like the GeForce 7900 GTX SLI.
When NVIDIA introduced the GeForce 8800 GTX last year, they were quick to point out the GPU’s ability to scale to additional cards. At the time, they were mum on what their specific plans were, but now we can finally reveal what that second SLI header on the GTX and Ultra is for: 3-Way SLI!
“Who needs 3-Way SLI anyway?”
This is probably the first question someone who’s not intimately familiar with PC gaming would ask. “Exactly who needs three graphics cards anyway?” Obviously, 3-Way SLI isn’t intended for the casual gamer who occasionally plays a round of Counter-Strike: Source or World in Warcraft. This is for the guy who wants the best performance possible with the best image quality. If you lust after the graphics you see on the back of the game box – the high polygon characters with high-res textures and jaggie-free, 100% smooth edges – but also want blazing performance, 3-Way SLI is for you. As any gamer who’s picked up a cutting-edge title like Crysis will tell you, even with dual GeForce 8800 GTX graphics cards running in SLI, the frame rate can drop pretty quickly with the game set to its maximum settings.
Gamers with 30” monitors would benefit from 3-Way SLI as well. Going from two to three cards should allow you to game at 2560x1600 with even higher frame rates than a conventional 2-Way SLI setup would provide.
And by using standard off-the-shelf components like the nForce 680i and GeForce 8800 GTX/Ultra, 3-Way SLI should be more user-friendly than Quad SLI was. 3-Way SLI doesn’t run into the same DX9 limitations as Quad SLI, and NVIDIA has had a year to tweak the technology so it’s compatible with more games. All this should make 3-Way SLI more user friendly than Quad SLI ever was. That’s the theory at least. Today we’re here to find out how effective NVIDIA’s 3-Way SLI solution is in the real world.
So what will you need to run a 3-Way SLI system? Have a look at the following guidelines:
Now in theory you could use the PCI Express interface to link three cards together for 3-Way SLI without the connector, say for instance if you wanted to link three GeForce 8800 GTs, but the current 3-Way ForceWare 169.18 driver is limited to supporting just the GeForce 8800 GTX and Ultra GPUs only. We know because we tried running 3-Way 8800 GTS and GT SLI as an experiment once we were finished with our 3-Way GeForce 8800 Ultra testing.
You really wouldn’t want to do this anyway; over the course of our testing for this article our SLI cable actually came loose when running 2-Way tests and the cards weren’t scaling properly as a result: we were seeing 2-Way SLI performance improvements of 20-30% when the difference should have been closer to 50%. Going from two to three cards, the PCI Express interface would have likely been even less effective.
With three GeForce 8800 GTX or Ultra cards running in sync together, we should also point out that you’ll want a powerful CPU to keep everything running smoothly. Fortunately most Core 2 CPUs can be overclocked to speeds of 3.0GHz or greater with ease, so this shouldn’t be a problem for most enthusiasts.
Finally, all three cards don’t have to come from the same board manufacturer. You can mix and match cards however you’d like, with the only limitation being that they must all be based on the same GPU (i.e. you can’t mix a GeForce 8800 GTX with a pair of GeForce 8800 Ultras).
3-Way SLI Game Support
When Quad SLI debuted in 2006 with the GeForce 7900 GX2, only a select number of games scaled properly with the hardware. The GeForce 7950 GX2 improved the situation but again, due to the design of DX9, even it had its fair share of limitations; F.E.A.R. was the only real D3D app that scaled really well in multiple scenarios.
3-Way Gaming Bliss: Falcon Northwest Mach V
To showcase the performance of 3-Way SLI, we’re testing a Falcon Northwest Mach V system that has been equipped with the technology. The system Falcon Northwest sent over is a monster too, running a Core 2 Extreme QX6850 that’s been overclocked to 3.65GHz with liquid cooling.
Falcon’s attention to detail is legendary, these guys are the pioneers of the gaming PC after all, predating other manufacturers like Alienware and VoodooPC by years. Take the case for instance. Falcon uses a Silverstone TJ03 chassis and totally tricks it out. The Falcon logo is emblazoned on the front drive bay door. When you boot the system up it glows blue with yellow eyes, and of course you can’t miss the custom paint job. This is no ordinary paint either, if you’re an Acura MDX owner, you may recognize the color -- it’s Sage Brush Pearl. Falcon says it’s one of their most popular colors.
At the top of the case, Falcon has integrated a massive air intake. This intake supplies cool air to the CPU cooler and the rest of the system. Meanwhile, at the rear of the system, Falcon employs two Silverstone fans which exhaust hot air out the back of the chassis. There’s also an additional fan at the front of the system which supplies cool air to the hard drives.
The motherboard powering Falcon’s Mach V is EVGA’s nForce 680i SLI motherboard. The EVGA motherboard has proven popular with OEMs and enthusiasts alike because it’s powerful yet not as outrageously priced as some of the other nForce 680i motherboards on the market. It may not have all the bells and whistles of a high-end nForce 680i motherboard like the ASUS Striker Extreme, but its BIOS is quite robust, providing all the settings you need for overclocking. If you’ve been following our reviews for the past year, you’ve no doubt noticed the EVGA motherboard is the standard platform we use around here as well. GPU launches ranging from the GeForce 8800 GTX all the way to the latest GeForce 8800 GTS 512MB were tested on our trusty EVGA nForce 680i motherboard.
3-Way SLI Mach V systems Falcon ships to end users will actually utilize the newer nForce 780i chipset.
Running alongside the EVGA motherboard and Core 2 Extreme QX6850 are 4GB (4x1GB) of Corsair Dominator RAM. Corsair’s Dominator modules are another popular item among enthusiasts looking for maximum performance. The storage subsystem consists of a pair of 150GB Western Digital Raptor hard drives which have been striped together running as a RAID 0 array. A 1-terabyte Hitachi HDS721010KLA hard drive serves as an additional storage option.
Finally, last but certainly not least, graphics duties are handled by a trio of XFX GeForce 8800 Ultra graphics cards.
We’ll post a full evaluation of the Falcon Northwest system in the coming weeks. Now onto the benchmarks!
Crysis is without a doubt, the game that needs the power of 3-Way SLI the most. Even with a pair of GeForce 8800 Ultra graphics cards running in SLI, the frame rate can hit the single digits! Let's take a look at the game's performance:
Crysis – Direct3D
Even though 3-Way SLI support is still a work in progress, Crysis shows good scaling for 3-Way already in our opinion. Again, we couldn’t get 2560x1600 to run with 3-Way, but 16x12 and 1920x1200 both ran great and offer nearly a 30% performance increase with conventional 4xMSAA.
BioShock – Direct3D
In order to run BioShock with AA, we’re forced to rely on the game’s DX9 mode rather than DX10. Here we can see that 3-Way SLI scales well in comparison to the single card and 2-Way SLI setups, particularly at 2560x1600. At that res, 3-Way provides a performance boost of about 2.7X over the single GeForce 8800 Ultra card, and 1.4X over the 2-Way SLI system. Even at 1920x1200, we also saw a nice increase in the minimum frame rate, although obviously the margins separating 2-Way and 3-Way SLI are much slimmer.
Company of Heroes – Direct3D
Company of Heroes also scales well with 3-Way SLI. At 2560x1600, the 3-Way system ran a little over 2.7 times faster than the single GeForce 8800 Ultra. Again, the margins are obviously going to be slimmer at 1920x1200 as the graphics cards aren’t being pushed as hard. In this case, the 3-Way SLI user at 1920x1200 may want to crank up the AA level to a higher setting like 8xMSAA or 16xCSAA.
Call of Duty 4 – Direct3D
Call of Duty 4 doesn’t seem to tax the graphics subsystem as hard as the previous titles, and thus 3-Way SLI doesn’t scale as well here. At 1920x1200 performance is basically even among the SLI rigs, only at 2560x1600 do we really see the 3-Way SLI setup begin to pull away, running 22% faster than a conventional 2-Way SLI system. The single GeForce 8800 Ultra trails significantly behind the other configs though.
Lost Planet – Direct3D
Lost Planet is one of the more demanding games we test here and it really shows in the 3-Way SLI benchmarks. Going from one to two cards we see excellent scaling, and 3-Way scales well also. Even 2560x1600 is pushing the 3-Way system though.
Oblivion – Direct3D
We were pretty surprised by the 1920x1200 results with Oblivion under 3-Way SLI. At that resolution the cards didn’t seem to scale any better than the 2-Way config, and we noticed some tearing when scrolling through the Oblivion menus. Once we loaded up our saved game the tearing went away, but as soon as we went back to the menu, it came back. It was an odd issue that didn’t occur with single card or 2-Way SLI testing, and it may have affected our results at 1920x1200.
F.E.A.R. – Direct3D
HL2 Episode Two
Episode Two is built around the oldest game engine in this test, Source. As you probably already know by now, Source runs quite well on today’s latest hardware already, you don’t need to invest $1,000+ to get good frame rates out of Half-Life 2 Episode Two, a Radeon HD 3850 or GeForce 8800 GT would be more than enough for this game. Even with the game’s settings cranked all the way up, and NVIDIA’s maximum 16xQ CSAA mode, 3-Way SLI yields no more performance than 2-Way. In fact, it ran a little slower in our testing, which is likely due to additional driver overhead.
While 3-Way SLI is targeted towards users with 24” or larger monitors running at 1920x1200 or better resolution, we realize that there are many of you who are perfectly happy with your high-end 20” LCDs who are limited to 1600x1200, yet curious to see how 3-Way SLI would stack up on your system. So we decided to run some benchmarks at 16x12 with the AA level cranked up to 16xCSAA (note, this setting is less demanding than 16xQ). Let’s see how the cards stacked up in games at this setting:
Of course, due to the extraordinary expense of 3-Way SLI, we don’t see this technology taking off anytime soon. You’ll have to invest in a $200+ nForce 680i or better motherboard, a 1,000W power supply, and three GeForce 8800 GTX or Ultra graphics cards; and don’t forget the 24” or 30” monitor. So clearly this technology isn’t designed for the average consumer who doesn’t game heavily. 3-Way SLI is intended for the hardcore gamer who craves the very best performance, and wants the best image quality available. For this type of consumer, NVIDIA's 3-Way SLI solution clearly delivers: this is the fastest graphics platform on the planet right now.
This is a very niche market, but clearly a market that both AMD and NVIDIA must feel is viable. After all, neither company would have spent the considerable R&D time and resources on this if they didn’t feel there was a market for it.
As we’ve told you in the past, the graphics subsystem plays the most significant role in gaming performance. Not the CPU. So if you want the best gaming performance possible, you should spend more money on graphics than the other system components.
With that being said though, we are disappointed that 3-Way SLI is only supported by NVIDIA’s most expensive GPUs, the GeForce 8800 GTX and 8800 Ultra. While we realize that it’s the high-end GPUs that will show the most benefit thanks to the larger frame buffer and wider memory interface, there aren’t a lot of gamers who are willing to fork over $1,500 or more on their GPUs alone. It just isn’t practical for the enthusiast on a budget who would like to take advantage of 3-Way SLI.
NVIDIA needs to expand 3-Way SLI to cheaper GPUs like the GeForce 8800 GT and GTS 512MB. In theory, AMD already provides 3 and 4-Way CrossFire to GPUs dating all the way back to the Radeon X1950 Pro from last year, so there’s just no reason why NVIDIA shouldn’t trickle 3-Way technology down to other GPUs. Hopefully this issue will be addressed by NVIDIA shortly.
In the meantime, 3-Way GeForce 8800 Ultra/GTX is here now and its a screamer when it comes to performance. If you can afford it, this is as close to gaming nirvana as it gets...
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