techneutral :
The R9 290 has better core speed (947mhz vs the GTX 770, 863mhz). It also has more GPU memory (4096mb vs 3072mb) and more memory bandwidth (320 GB/s vs 288.4 GB/s). Recommended ram for the R9 290 is 8 gb, recommended ram for GTX 770 is 12 gb.
Other side: the GTX 770 has less power consumption, has a better actual shader performance, and a better memory speed.
Honestly, I would go for the R9 290
that is not the right numbers if you pic a Nvida card for the same price the nvida card is gona be something like this
coreclock 1059 MHz boost 1111mhz
4gig ram
mem Clock on all 770 7.01 GHz
256-bit
and picking a evga 770 will be even faster.
i would pick nvida enyday aslong as they are in the same price range,dont get foold by the memory bit rate.
and nvida has better driver overclocking software Everything, And they dont just relese the same card whit just a diffrent number unlike amd.
Just so you dont Think im just a nvida fan i use a amd my self due to price.