All that talk about Core i5/i7 vs. Core 2 Quad made me think back to how I viewed my old Q6600 system.
I figured that once I had the clock speed jacked up, it would be sufficient for gaming, right? Well, about six years in (2013), I got a pretty hard wake-up call in the form of PlanetSide 2. The framerates were generally pretty terrible, but the FPS counter did something most game engines don't - tell you if the CPU or GPU wasn't the limiting factor.
It wasn't the GPU, even with a GTX 480.
That's what pushed me over the edge, resulting in the i7-4770K build I have now, and framerates went way up - in PlanetSide 2, in DCS World, and in all those other heavily single-thread-bound titles that have cropped up over the years, despite all those Sandy Bridge holdouts saying that games want GPU more than anything, all on that same GTX 480. I knew I had made the right choice.
Now I'm seeing stuff like BeamNG.drive that performs awfully on that Q6600 even pushed to 3.6 GHz on water where my i7-4770K doesn't break a sweat, recent games that require SSE4.1 to run and thus will not run on that computer unless I felt like giving it a Penryn upgrade (which would be wasting money at this point), and all in all, it seems like it's a waste to keep that 50% overclock when modern CPUs make Core 2 look like Pentium 4 in terms of the IPC difference. Oh, and this is all with a GTX 760 to replace the now-dead GTX 480, and that 480 was already being bottlenecked as is!
It's not often that we can say that a single CPU remains viable for 5 or 6 years, though. I still remember the ludicrous 1990s/early 2000s pace of CPU speed boosts to the point where you'd literally have to spend $1,000+ on a whole new computer the very next year if you wanted to get decent performance (read: consistent 60 FPS on high/max settings) in titles like Quake, Unreal, and their numerous sequels with increasingly demanding versions of their engines.
And, hey, if you're not all about silky-smooth gaming on the latest titles, it'll hold out longer than that. The same Q6600 CPU/mobo combo is about to see its 9th year of service come November, and my little bro's enjoying it for PC gaming just fine, even with slideshow framerates here and there. It also doesn't choke on modern Web sites the same way a PowerPC Mac or a Raspberry Pi Zero does, making it viable enough for general computing.