I use the 204 AND an almost identical setup to you, except I’m running an Intel chipset on a little NUC. Jack_iodelay latency measured 11 times, buffer = 1024, periods 3 I played live with a midi keyboard connected to sound card Midi In.īehringer UMC204HD Supported sample rates and bit depthsīEHRINGER UMC204HD 192k at usb-0000:41:00.3-1, high speed : USB Audio One midi track with a-Fluidsynth loaded with “soundfont-fluid”. Sample rate 44.1 kHz, Buffer: 64, Periods: 3 Manjaro with realtime kernel: 5.4.61-rt37-MANJARO, Performance - governor turned on. Motherboard: Asus_ROG_STRIX_X399-E_GAMING_TR4 I’ve seen other people having problems getting 204HD to work without xruns with 64 buffer, 3 periods so I guess the motherboard plays a role here. The a-Fluidsynth “CPU Profile” showed the same load regardless if Ardour DSP load was 30% or 5%.

I saw this behavior many times (but not always) and it probably indicates something is be wrong with the RT-kernel I used (or my system). The DSP load varied between 25% - 30% when using buffer: 64 periods: 3, However after playing for a while the load sometimes dropped down to 5% - 10% and stayed there. 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.

Driver umc404hd