I'd start by overclocking your i5 more.
Perhaps 4.6 - 5.0GHz depending on heat and your case cooling.
Since GTA5, BF1 and Forza are all CPU demanding games.
Beyond that, I'd hold off on any purchases of Ryzen or KabyLake, until Ryzen is released to the public, and we know how it compares.
If at that point, you want a new shinny system, at least you can make an informed decision, based on prices, benchmarks, core count and overclocking potential.
I personally feel that all Gaming PC's need to be Quad Core minimum, going forward.
Yes, 4 Core i7 Intel processors have great IPC, but realistically looking at console's (PS4 Pro + Scorpio)
There all 8 core multi-threaded systems, they will be the standard that all AAA titles will be optimized to use.
Just look at BF1 or GTA5, the love 6-8 Core systems.
Personally going forward in the next year or two I'll be investing in a new system, with a 8 Core CPU, just so the system will last another 5-6 years, with demanding multi-core games.
