what do u mean by faster ?
the base current start with high value , then it will decrease.
i was asked about the maximum frequency of switching of transistor?
I believe the applicable term for this capacitor is that it is a "speed-up" capacitor. PRS has characterized the purpose of the capacitor nicely. The idea is that the impedance of the capacitor being an inverse function of the frequency of the signal applied to it. The net impedance of the capacitor and the resistor across which it is placed decreases as the frequency of the input signal increases. The result is that the input signal drives the transistor harder at higher frequencies.
It's guesswork with no component values, but the capacitor can be a high pass filter around the one base resistor, leading to faster turn-on with increasing frequency.