At 4k res, turn off AA completely. It isn't needed at that resolution and will completely waste GPU resources. At 4k, I'm seeing a solid 120fps minimum on most games. AA is off and AF is on 4X[forced through the driver]. Performance is smooth and fluid. And before you argue, TRY IT!
If you think you don't need AA in 4K, then you need to get your eyesight checked.
AF at 4X is going to give you terribly blurred textures in certain angles. Not even a Titan Xp can pull the heaviest current games in 4K at 60 Hz at the highest detail level, so a gaming console with a fraction of the performance is certainly not going to do that.
The claim was a 3 ghz quad Kaby has twice the power of a 2.3 octo jaguar. What would the IPC difference have to be?
IPC is performance per core. Of course more cores may provide more total theoretical performance, but in real workloads things don't scale like that. And since we're talking of a gaming console, more cores is certainly not going to mitigate the slow single core performance.
The task of rendering can only be split to a small degree, so in any game the performance of a single core is the deciding factor for real performance. The other cores mainly help to do non-rendering tasks, OS tasks etc.
To estimate IPC you take one or more (scalable) benchmarks, and divide the score by clock speed.