I am trying to determine the roundtrip latency of a dusty old Toneport UX8 audio interface I have laying around, and I am getting some unexpected results.
I am testing using CEntrance ASIO Latency Test Utility, output 1 cable plugged into input 1, the channel strip led blinks to confirm that a short audio impulse is indeed sent output to input to measure the actual roundtrip latency.
I am getting 2.75 ms for 128 sample buffer and 5.42 ms for 256 sample buffer, which is unrealistically low, it is about 0.1 ms (converters latency perhaps?) above the minimum theoretical input latency. Seems like the output latency is missing from the timing, plus there should be also additional latency from the USB bus - at least like 2 ms. The results are consistent across tests.
Those results are in sharp contrast to the ones reported by Cubase, which reports 4.8 input / 9.6 output and 7.5 i / 15 o respectively - the input latency alone is higher than the one measures by the latency test utility.
Any idea what is going on here?