FIB milling with a Ga ion beam has very high time-efficiency, for instance, a typical milling speed of 1 nm/min on a 10 μm x 20 μm area of silicon (Si) at 1 keV with 150 pA at 30° tilt. However, higher milling rates are not always better since lower rates produce smaller damage and more precise control of finishing time.

In general, collecting data from a volume of 1 x 10⁵ µm³ with FIB milling with a Ga-ion beam requires several continuous days of automated data collection. Xe plasma focused ion beams (PFIBs) mill ten times faster than Ga FIBs.