Yeah maybe you are right for Skylake client, I haven't tested carefully there, but I'll probably get around to it. This thread [1] indicates that it may have only been Haswell that had the halted portion.
On to Skylake-SP, however, that chip is reported to have both reduced throughput and fully halted periods in [2].
Some have speculated it has to do whether chips have an integrated IVR: the models with integrated IVR having less capability of handling high dI/dt events. I don't know about that though (Skylake-SP still has external VR, right?).
