We started this review with single monitor gaming in mind. The reality is that with graphics cards so powerful only 2-way SLI is a viable solution unless you really use the hottest games that are GPU limited. Once you reach a monitor resolution of 2560x1440 or 2560x1600 that's where a third card starts to make a difference, albeit too little to really justify the money.
So our recommendation is that with a single monitor setup like 1920x1080/1200 your maximum number of GTX 680 cards set up in SLI should be two. Now, if you have that nice 30" monitor with a 2560x1440 or 2560x1600 resolution, that's where that 3rd card could matter.
Obviously there's something else to consider, and we'll probably address this in another review, it's multi monitor gaming. If you're going to be using 3 monitors at 5760x1200 that's where a 3rd card would make some sense.
Processor power then. Each time we publish an article on multi-GPU solutions we read it on the forums, 'you should be using a faster test platform'. Hence we doubled up the results in this review with a X79 / Core i7 3960 Extreme processor clocked at 4600 MHz. These two components at 1200 EUR (excluding the liquid cooling) do show a definitive increase in performance. You do need to wonder though if the ~15% performance increase really justifies that money... but obviously if you can afford three GTX 680 cards, you probably will go for the best and fastest infrastructure as well. X79 has another advantage, it is PCIe gen 3 compatible -- albeit NVIDIA's current driver only supports PCIe gen 2.
What surprised me very much was 3DMark Vantage and 11.
I mean there was a 10K difference in the Vantage GPU score and nearly 4000 points in the 3DMark 11 P score between the Core i7 960X 3.8 GHz and Core i7 3960X 4.6 GHz, that's just very substantial and not representable of what you see in gaming.
So performance wise, up-to 2-way very little negative can be said about the GeForce GTX 680 set up in SLI. 3-way however is a tough nut to crack.
GPU heat will hardly go up depending on your configuration and remains acceptable to slightly high only, make sure you have everything properly ventilated though as three GPUs equals 3x the heat that needs to be exhausted.
A third card in gaming under stress does make the setup a good notch louder, do keep that in mind if you are a little anal about noise levels. But X79 / 3960X~3930K / Quad Channel memory / 3 monitors / 3x 680... my bet is that you are going liquid cooling anyway. SLI is expensive, you are in the extreme high-end arena, it has never been any different.
Power consumption then, two GPUs consume roughly 350 Watts whilst three GPUs use roughly 510W, add to that the rest of your system (processor, chipset peripherals) at say 200 Watts and you'll find yourself in the 700 Watt power consumption region when playing a hefty game. If you plan to overclock CPU and GPUs, then make sure you add another 200W onto your PSU requirements. Keep that in mind okay, increased voltages means increased power consumption.
Bear in mind though, to be able to operate two or more cards in SLI mode you'll need a SLI compatible motherboard, most Intel X58, P67, Z68, Z77 and X79 motherboards are SLI certified, some P55 motherboards as well. AMD's 900 series carry SLI support as well. Carefully make sure and check that out before opting for your SLI preference and thus before purchasing multiple cards.
Driver compatibility - In all our tests we had no driver issues whatsoever. All games worked straight out of the box.
So there you have it, three GTX 680 cards set up in SLI will still cost you say 1350 EUR alone, for that money you'll gain a truckload of performance kicking your configuration into the highest gear performance wise. We'll admit it though, if you are on a single monitor, there's just no need for it unless you like to break 3DMark scores.
However, if you are gaming on a nice 30" monitor or are planning a multi-monitor setup for 3-way SLI, only there would this setup make sense. And that makes 3-way SLI with the GTX 680s only something to consider for the ones that plan to go awfully extreme. But that's never been any different of course.
Thanks go out to Point of View for sending out the two GTX 680 cards, we hope you liked this review. Until next time.
KFA2 GeForce GTX 980 Ti HOF Review In this review we benchmark the new KFA2 / GALAX GeForce GTX 980 Ti HOF, a product that impresses by design as it offers great game rendering performance at quiet noise levels. Hey with its white desi...