This page is for documenting the (round-trip) latencies between data acquisition, availability of data on the host PC, and generating a response (in the simplest case just a trigger output).
Reducing the latency is one of the major points that we're trying to improve in order to enable better closed-loop experiments.
USB2.0
The round-trip latency (acq board to computer back to acq board) is around 20 ms—sufficient for a variety of experiments involving closed-loop feedback. This duration can be shortened by changing the size of the software buffer (down to approximately 10 ms, depending on processor speed) or switching to PCIe. USB 3.0 doesn't actually gain you much, since there's a lot of overhead involved in sending each buffer. The smallest practical buffer size is more important than the overall transfer speed.
USB3.0