TechPowerUp came across a bunch of leaked benchmark results that allegedly reveal the performance of AMD's Radeon R9 290X and
Radeon R9 280X. If these results can be trusted, it looks like the Radeon R9 290X will beat the GeForce GTX 780 but be typically slower than the Titan, while the Radeon R9 280X is slower than the GTX 780. Somewhat worrying though is the power consumption chart, the Radeon R9 290X reportedly uses 62W more in load than the Titan and 80W more than the GTX 780!
The tests present some extremely interesting results. Overall, the Radeon R9 290X is faster than the GeForce GTX 780, and trades blows, or in some cases, surpasses the GeForce GTX TITAN. The R9 290X performs extremely well in 3DMark: FireStrike, and beats both NVIDIA cards at Metro: Last Light. In other tests, its half way between the GTX 780 and GTX TITAN, leaning closer to the latter in some tests.