The EM disturbance to Earth (Dst) of Carrington was -1000, whereas this one was -250. But the flare that produced Carrington was estimated to be an X80, whereas our max was around an X3.98. I think that means that Carrington produced around 0.008 W/m^2 of X-ray flux whereas ours produced around 0.0004
The non-linear effect (20x weaker flare only 4x less effect) is accounted for by how Earth's magnetic field has weakened in the ~165 years since Carrington.
The non-linear effect (20x weaker flare only 4x less effect) is accounted for by how Earth's magnetic field has weakened in the ~165 years since Carrington.