Our Mx magnetometer is a miniature optically pumped atomic magnetometer constructed with microfabricated components. This device measures the spin precession frequency of 87Rb atoms to determine the magnetic field by use of the Mx technique. It has a demonstrated sensitivity to magnetic fields of 5 pT / Hz1/2 for a bandwidth from 1 to 100 Hz, nearly an order of magnitude improvement over our previous chip-scale magnetometer. We have also increased the 3 dB bandwidth to 1 kHz by reconfiguring the miniature vapor cell heater.