The buffer memory is the data holding memory provided by the device and is used for analog input/output.
Sampling at the device's minimum clock is possible as long as the number of samples fits in the device's buffer memory size.
Whether or not sampling is possible with the number of samples exceeding 
 the buffer memory size depends on the sampling clock period, CPU processing 
 capacity, load status, USB line load, etc.
Maximum number of samples against the buffer 
 memory size of the USB device
In addition to the data of "number 
 of channels x number of samples", buffer memory of one data per sampling 
 is used as accompanying data.
In addition, 1 data is used fixedly.
Therefore, the number of samples that can be sampled only with the buffer 
 memory is
(buffer memory size / (number of channels + 1) ) - 1.
For example, in the case of a device with buffer memory 1K data (1024 
 data)
When sampling 1ch, the number of sampling data that can be stored is 511 
 times.
Sampling 2ch is 340 times, sampling 3ch is 255 times.