It's well documented that "ultra" settings on PC games can have a disproportionate effect performance compared with the visual benefit they bring. For example, here's a benchmark of Ghosts showing around a 50% performance increase from dropping settings down from Ultra to Extra:
http://linustechtips.com/main/topic...and-1440p-benchmarks-and-graphics-comparison/
And there are tons of extra effects going on in the PC version of Ghosts compared with the PS4 so it's entirely possible the PS4 is running at lower than "Extra" settings although an exact comparison is impossible without knowing this.
Also, quoting the 4.5 TFLOPs as the only measure is hardly accurate. Shader and texture performance may be off the scale compared with the PS4 but memory bandwidth and ROP throughput are only around 65% higher.
I think that goes without saying but it's a matter of to what degree? As far as I'm aware no developer has specifically stated that they can effectively match or exceed anything the GTX680 can achieve in a PC using the current consoles.
But in the end it obviously comes down to how well optimized each of the versions of the game are. I'm sure that a very well optimized game on the PS4 could match the performance of the same game on a GTX680 if the PC port was fairly terrible. But what if the PC port is very good? What if it makes heavy use of NV Gameworks or Mantle/DX12 features? Or even if it has a specific code path each for Kepler and GCN? Would the consoles still be able to match the performance of a GTX680/HD7970?
It's not really hearsay given that videos of in game action with frame rate counters have already been posted. Here's another for good measure:
https://www.youtube.com/watch?v=JtnHrdQFcDM
I grant the run through from the russian website that provided the detailed benchmarks was too basic to be comparable to DF's test but the 3 YT videos I've posted all feature some heavy combat but non of them get anywhere close to sustained drops in to the mid forties.
I'm not sure it matters exactly how the settings compare since it's already been established that there's lots moire going on in the PC version. That straight away invalidates any performance comparisons to the PC version running at maximum and thus CoD Ghosts cannot at this stage be used as some kind of evidence that consoles are performing at 680 or above levels.
If the developers would tell us exactly how the settings compare (like Crytek did with Crysis 3) then we'd be able to run apples to apples comparisons but all we know as of now is that the PC version does a lot more and also runs a lot slower. So nothing really.