If you intend to play on a 4K monitor, or across three monitors, I'd get the Sapphire for the additional VRAM. For a single 1920x1080p monitor though, the VRAM difference won't matter, and for those few games that use it I'd rather have PhysX. Also, the Windforce 3 cooler is very good, and very quiet.
Edit: the GTX780 and R9 290X are on the same tier, which means they will trade blows depending on the game; neither is universally faster than the other. For most games, even at UltraMaxOhWOW settings, frame rates should be high enough that I doubt you'll notice a difference. If I were the one buying, I'd choose the GTX780 over the R9 290X, largely on the merits of the WF3 cooler. Note that it will be a big card, so make sure it fits, and that your PSU is up to the task.
r9 290x all the way. The 290 can run some games at 1440p max @ 60fps. r9 290x is a little bit below the 780 ti. For multiple monitors the 290x is better for multiple monitors because of its higher memory bus.
hmm well my monitor is gonna be samsung 23.6 inch pls monitor , as i wont be able to get a higher resolution monitor , so i think i will only run games at 1080p , so in that case the GTX 780 is better right ?
now im a bit confused , at first i thought at the 1080 p resolution the 290x and 780 wont make a diff , but the last 2 replies said it will , also , i heard about heat and sound problems from the 290x , is that true ?
Okay firstly, if you game at a 1080p , people are right, both cards can hit fps higher than 60fps easily, and after that, you can't really notice the difference between each one on a 1080p monitor, but, since the r9 290x has 4gb of vram, it helps you more for the future if you decide to go more monitors, or higher res. monitors also, yes, that is true, hence that is why i said to get a aftermarket r9 290x, the price of these are less than some 780's and the temps are very good also
The GTX 780 and R9 290/R9 290x are very similar in performance, and to be honest I'd go with the GTX 780. Both the GTX 780 and R9 290x will provide similar performance on a 1080p monitor; the additional VRAM of the R9 290x won't provide much of a noticeable difference for you, if any at all.
Many users usually report issues with the build of AMD cards on Amazon, Newegg and other retailers; whereas Nvidia don't tend to have "bad" reviews.
Regardless of all that being said, I would still go for the GTX 780.