While the reply about your system handling it no problems is mostly correct, the older architecture and lower clock speeds of the 4770 will limit performance to some degree, especially on lower resolution/higher frame rate of say a 1080p 144Hz monitor. Ironically, at 1440p or 4K the load is shifted from the CPU to the GPU.
I've got a GTX 1060 6GB and even it gives better performance now that I've overclocked my i7-4790K from 4.4 to 4.8GHz.
DDR4 speed only impacts minor games like ROTTR and video editing and other stuff, DDR4 speed is only mainly good for ryzen since their architecture is based that way.
For games its always same, the difference in perfomance only increases at 4000+ but best all round is 2666MHz and difference in perfomance from all kits is 5%-10%.