Thanks for the response. The ADC timing mode is indeed set to "High Speed". I have 4 channels on the device, each set to voltage mode, and am reading from one of them using an AIn32() function, and am seeing that each read is taking right around 100ms (it's much slower - 400 to 1100ms in the other ADC modes). You say that "The AIn32() function is system dependent when acquiring data, especially in a loop", so I guess that's what I'm seeing. Surprised that it's so slow, but will look at using the AinScan() method.