Physx On vs 290 being off scroll down to Apples vs Apples its 2 fucking FPS at the same resolution and settings.
As for no SSAA yes because everyone plays games that run like shit with a minimum that regularly drops to unplayable levels On that graph posted i can count at least 12 occassions where the 290X drops to unplayable rate many times it happens back to back thus unplayable. Fun to look at but worthless as a comparison because I don't know anyone that plays games at unplayable settings just for Lulz.
2560x1600 Max settings SSAA off PhysX off = 38 vs 37 on the minimum and 54 vs 52 on the avg vs a Stock GTX 780
Honestly doesnt matter what benchmarks anyone pulls depending on the review and the reviewer the cards trade blows they are equals and it shows.
It seems that u missed this part on Hardocp
For our comparison we are comparing the R9 290X to the GTX TITAN, GTX 780 and Radeon HD 7970 GHz Edition, all stock reference video cards. We are using the default "Quiet Mode" setting on the R9 290X for our normal highest playable settings and apples-to-apples testing.