This is a load of crap, pure FUD that only people who build for e-peen need for re-assurance. Example:
http://www.techspot.com/review/972-intel-core-i3-vs-i5-vs-i7/page5.html
Core i3 with 2 SMT cores is plenty for almost any modern game. Is it ideal? No there are few exceptions, but getting anything more than an i5 for gaming is just FUD. i7, and most certainly 6 core SMT i7s only have value for CPU intensive workloads like rendering or encoding.
And mind you, these tests were at 1080p.... if you step to 1440p or god forbid 4K, the differences become decimals of a percentage. Gaming is 99% GPU bound, when will people learn this?
If you're building a system to game on, other features will push you to another platform before your CPU even becomes the bottleneck. It's been like this for the past 10 years, and it will keep being like this for the foreseeable future, at least until we keep rendering through DirectX. People with gaming systems with
i5s and a 980 are smart, they put the money where it's needed for gaming instead of wasting it.