Going into this article, we somewhat expected to be showing readers how much better dual GTX 970 cards perform at UHD 4K than R9 290s. This expectation was based purely on the fact that we saw a single GTX 970 beat the R9 290 by a 16% margin at 2560x1600 while consuming less power when we reviewed it last month.
At the time the GTX 970 was also much cheaper, but with recent AMD price cuts the R9 290 is now slightly more affordable than the GTX 970. With AMD's pricing now in check, the R9 290 in Crossfire compares a surprisingly well against Nvidia's newer GTX 970s in SLI, with the latter offering only 3% more performance on average.
Scaling wasn't an issue either as two GTX 970s were on average 86% faster than one. The problem for Nvidia appeared when playing games at the Ultra-HD 4K resolution, which slashed performance in most titles by more than half of the figure we saw when testing at 2560x1600.
Overclocking didn't help much either as the GeForce setup was still just 4% faster. Of the seven games we tested at 4K, the Radeons were faster in three while the GeForces won the other four. However, at 2560x1600 the GTX 970s beats the R9 290s in everything, often by a land slide.
The GTX 970s also uses around 10% less power, but that's negligible if we are honest. So to break it down, the GTX 970s are on average just 3% faster, use 10% less power, but also cost 10% more. They also overclock better, but overall the performance remains much the same.
Had AMD not been so quick with its price cuts, the slightly faster and more efficient dual GTX 970s would have been the obvious choice for 4K gaming, but as it stands, a pair of R9 290s in Crossfire are technically a better value as they simply deliver more frames for the money.
That said, I still prefer the GTX 970s as they are cooler, quieter and use less power, plus I'm not convinced we're seeing everything dual GTX 970s have to offer at 4K. There was too much of a performance drop from 2560x1600 -- a drop that didn't impact the Radeons nearly as much.