Just to support all of the above, this is an interesting article which illustrates such a case very well:
http://wccftech.com/fx-8370-i5-6400-gaming-comparison/
FX-8370 trumped an i5-6400 both at stock and overclocked by a fairly clear margin. I bet if this test could hypothetically have been run five years ago. the i5 would have been the victor. Why? Because it's taken all this time for game developers to really start utilizing multi-core properly. The Bulldozer series wasn't actually a bad design, it just gambled on software developers taking advantage of it which they didn't. Now that they are, Piledriver CPUs are actually improving in a sense.
So yes, an 8c/16t AMD chip even with lower IPC, could be a very powerful chip and competitor to Skylake maybe.
I have to admit i'm a little surprised by those results, i know the chip is capable of it under the right conditions but i didn't think the right conditions would ever come to light.
The problem for the architecture is quite simple, its nothing like an Intel and everything likes to treat any chip as if its an Intel, that doesn't work too well for the Bulldozer design.
The design is actually very clever, its programmable, first and still the only programmable consumer CPU.
Its modular design is often cited as a fault with it, that shows just how little its understood.
2 Integer Units in a dual 128Bit FPU (One module)
You can tell the dual 128Bit FPU's to combine to form one 256Bit FPU powered by one fat Integer Unit
Put simply it acts as a normal 8 core 8 thread CPU, or as a big fat 4 core 4 thread CPU, or any number of combinations.
If FP performance is what you need you tell the two FPU's in the module to combine for a nice fast 256Bit FPU.
If integer calc is what you need you would thread it through dual thread configuration to give you 8 threads.
If doing a combination of those you mix it up.
This design is a bit like having multiple CPU's on a single die.
With the FX-9590 i have set a video render going and then played BF4 while it was running in the background, i have never been able to do that with the 4690K.
The problem; because its seen as an Intel chip by almost everything it treats it as an 8 core 8 thread CPU only, so that low threaded FP performance that is so important for DX9, DX10 and even DX11 games, its requested simplistically by one or more of its 128Bit FPU's, not the combined fast 256Bit FPU that it would get if the Engine made the correct request to it.
The only engine i knew of that used these CPU's as intended was Cryengine, probably something to do with the fact that Crysis 3 was developed in partnership with AMD.
Result: An FX-8350 was faster than an i7 3770K in that game.
Now here is the thing, AMD had the option either to accept Intel's dominance and chose be an Intel clone knowing that way it wouldn't matter that its not an Intel, or they could do something different, something a bit new, a bit more advanced and perhaps a bit better but you would need to change the industry to your way of doing it.
AMD chose the latter.
Make your own minds up about AMD's choices.
Having said that, it looks to me that Zen is simply an Intel clone.
AMD learnt a hard lesson, a victory for the technology status quo.
