The test was done playing piano on fluidsynth. 64 buffer and 2 periods worked sometimes flawlessly and sometimes threw xruns. Both devices were able to go down to 64 buffer size and 3 periods without xruns (tested for about 1 hour). This is probably some kind of a bug in the firmware of the device.īehringer UMC204HD and UMC404HD are both capable of a very low latency. Unplugging and plugging the USB cable returned the device to normal operation.
One “flaw” that I noticed was that when UMC204HD was connected and I rebooted the computer the device “disappeared” from Linux. Neither device has a power button, so they turn on when you plug power to them. UMC404 is powered by a separate power supply. UMC204HD does not have a power supply, it gets its power from USB.
