Benchmarks: Crysis 3, BioShock
The Radeon HD 5870 averaged just 22fps at 1080p while the HD 6970 was a little over 40% faster at 31fps. The HD 7970's average frame rate of 38fps was 23% faster than the 6970 and the jump from the 7970 to the 7970 GHz Edition only yielded an 8% increase for 41fps, but the R9 290X managed to top the GHz Edition by 41%, which was the same gap between the 5870 and the 6970.
The results at 2560x1600 were considerably different as the 6970 was only 31% faster than the 5870, the 7970 was a significant 41% faster than the 6970, while the R9 290X was still around 40% faster than the 7970 GHz Edition.
At 1080p in BioShock the HD 6970 was just 26% faster than the 5870 while the 7970 was a whopping 69% faster than the 6970. The 7970 GHz Edition provided an extra 10% more performance over the standard card and the R9 290X was just 25% faster than the 7970 GHz Edition with an average of 111fps.
Again, increasing the resolution to 2560x1600 changed the margins a lot. While the 6970 vs. 5870 comparison remains much the same, the 7970 was now 78% faster than the 6970, yet despite that the R9 290X was now 35% faster than the 7970 GHz Edition.