The MOSFET datasheets have a very important factor called Total Gate Charge and is given in nC.
It is actually the time * current at which the MOSFET is fully on, for example when you read 100nC it means that if you give 1A (limit the gate current to 1A is what i mean) the gate will be charged after 100ns (100nC /1A = 100ns ) or if you give 10mA the gate will be charged after 10000ns (100nC /0.01A = 10000ns ) etc
So when you choose a MOSFET and driver you should consider the parameters for both of them (MOSFET with lower nC are faster)
For mode details you can read
https://www.fairchildsemi.com/an/AN/AN-9010.pdf
see page 17 for the different gate capacitance charge stages
Once the mosfet is conducting , when you want to turn it off you need to discharged the gate capacitor, the faster you discharge it the faster it will turn off.
In simple switch application you may just stop driving the gate but when you are using a high frequency and you care about the speed you have to use a push pull circuit to give or pull current fast.
In addition when a mosfet is neither on or off and is in the between stage it gets hot because of the current multiplied with the voltage drop across the source-drain, when it is off you have no current and when it s on you have very small voltage drop (because of low on resistance).
I don't think you gen get away with a few mA drive for PWM switchin even if it is 1KHz, you will have heat problems and low efficiency.
Alex
---------- Post added at 13:25 ---------- Previous post was at 13:14 ----------
Also check this
**broken link removed**
Alex