I haven't noticed any CPU spikes. The framerate doesn't seem to drop when it's happening and everything else seems normal ie you can see the other players happily moving about and shooting each other. If the CPU was maxing out, there would also be a drop in framerate(as was evident the last time I played PS2) as well as a failure to respond to inputs. I have an AMD x6 1090T and very few things can max out my CPU. I run quite CPU-hungry audio apps and run a ridiculous amount of FX, and my RAM is maxed out way before my CPU. I also sometimes run number-crunching tasks for CERN and protein-folding simulations which are also capable of maxing out my CPU. I somehow doubt that BF4 is as CPU-intensive as those. If it is, then it's likely to be due to a bug. I will check when I next play as I'm not sure it isn't due to CPU load.
[edit] just played with the browser open and while there were some small CPU spikes, none of them were suffcient to max out the CPU and the load was balanced fairly evenly across cores. The game froze when I spawned in and there was a RAM spike that occurred for about a second and the RAM used decreased steadily after that, but the game failed to respond to any input for about 10 seconds. I don't know that the RAM spike was the cause of the problem, but it could be the culprit. I will try again to see if there is any connection between the RAM and the freezing issue.
It's taken me a while to get the problem to occur again, but this time I noticed that there was a very clear 100% CPU spike for a very brief time ie every core was showing 100% usage, but the game did not start responding again for about 10 seconds. The RAM usage was also very high, but it didn't look as if anything unusual was going on. Again, there was no obvious drop in framerate, probably because of the short time it took for the spike to occur.
Well I'm glad to have given a little insight. It took me forever to figure out why my machine was doing that but I was easily able to duplicate the problem while attempting to stream.
I haven't been keeping up with things to know if there are any optimizations in the works but hopefully your problem is being looked at. If not you might want to try and find other players who share your problem and band together to move it up the chain.
Good luck!
I have a 360 controller also hooked up to my PC also, and was able to instantly fix the behavior by tapping the controller (which never stopped working) and then going back to the mouse (which suddenly started working again.
