Conclusion

Having a quick look at the results shows, that at 1080p the two configs are performing similarly on average. Increasing the resolution to 1440p gives the CrossFire setup a 16.8 percent advantage over the single GTX 980 Ti and at 2160p (UHD) the difference is 21.5 percent towards the 390 CF. Overall this shows that the CrossFire configuration can start to show it's muscles when you run games at high as well as ultra high resolutions and the fact that both AMD cards have been equipped with 8GB VRAM, really makes this setup suitable for UHD.

Apparently two Radeon R9 390 cards make for a powerful gaming setup. While the two cards together cost about 653 Euro, which is approximately 7 percent less than a single GeForce GTX 980 Ti, the increased power consumption is going to set you back quite a few bucks over time. Having a closer look at these numbers shows, our system with one GeForce GTX 980 Ti pulls 321 Watts from the plug, whereas the setup with two R9 390X pixel accelerators needs a whopping 695 Watts. In other words the configuration with two R9 390X cards burs almost 217 percent more power and that really is a significant difference. Overall it is interesting to see that at very high resolutions two R9 390X cards outperform a single GTX 980 Ti well measurably but unfortunately the performance advantage comes at insane levels of power consumption, which cannot be justified.