LabVIEW is much faster than 1ms, but software timing is limited to 1-2ms. Even that cannot be guaranteed on a multipurpose OS. For deterministic timing, you need to utilize hardware timing of your DAQ hardware or use LabVIEW RT of FPGA, for example.
10ns is awfully fast. What kind of function generator do you have and how do you communicate with it? How many points are in each 10ns chunk of waveform? Is this microwave? How many different functions do you have? Is there a repeating pattern?
Can you provide a bit more details on what you are actually trying to do? Seems quite unrealsistic.