maximum sampling rate

[kirtikant]

hi, 

    I am using a Picoscope 4423 using USB and creating a virtual oscilloscope in labview. I want to know what is the maximum sampling rate i can get. As of now i am unable to get more than 1M samples per second or in other words a sample interval of 1us. Is this the limitation of hardware or labview or my programming? I am able to reach a maximum frequency of 500KHz.

i have attached my .vi files below

[kirtikant]

UPDATE:

i am able to reduce the sampling interval to 200ns, below that it gives me an error saying "Invalid sampling interval". So 200ns means 5MS/s. which means the maximum frequency i can reach is 2.5MHz. But the device i am using has a sampling rate of 80MS/s when using only one channel. so i should be able to reach 40 MHz with it. I am not able to understand what is limiting my sampling rate?