Conclusion
Today we’ve had a look at SLI scaling of two custom GTX 980 graphics cards from ASUS in combination
with an Intel Core i7-5820K CPU, while driving the Intel CPU at default clock speeds. Our scaling index page shows an average performance bump of
50.16 percent in the case of 1080p when using two GeForce GTX 980 cards instead of one. A glimpse at our 1440p preset quickly reveals an even better scaling where the SLI system outperforms the single-GPU setup by
64.78 percent. In the case of our UHD preset the performance benefit is even
bigger and we see 67.33 percent scaling.
When it comes to playability we can say that one GTX 980 graphics card is sufficient to enjoy recent games on highest details and 1440p resolution. We were able to play all games, which are included in this article, smoothly without stuttering. Even Crysis 3 at 1440p and with all details maxed out didn’t drop below
30 fps. If we look at UltraHD in combination with very high details, we see that two cards are a must if you want to be able to actually play games. You might be asking why we’re testing these systems with UHD and all details maxed out, since the massively increased resolution
in combination with a 28 inch display already makes aliasing effects less visible. Our thinking is, that we want to find out where the limits of specific configurations are and in the case of two GTX 980 graphics cards we have to torture them with UHD and highest details in order to really see frame rates tumble.
Apart from the sheer performance also power consumption is very interesting to have a look at. In idle and with one card our test setup pulled
68 Watt from the wall and in the case of SLI we measured 84 Watt, which is equal to a 23.53 percent increase. Under full load we notice that the single card setup burnt
354 Watt and the SLI system was turning 515 Watt into heat, which is a difference of
45.48 percent. In other words our test systems gaming performance was increased by
50 to 67 percent, while power consumption rose by almost 45 percent. If we only look at gaming performance of the entire system and put it into perspective with the increase in power consumption, the results are
actually reasonable.