Typically there’s a couple of milliseconds (1-2 DMX frames) delay between your PC generating a frame of DMX on its processor and it being output as a DMX frame on all ENTTEC DMX USB devices (essentially un-noticeable and comparable ).

When inputting DMX this can increase to up to 2-3 DMX frames due to the additional processing required to read, send and interpret the values onto your computer.

It’s also important to consider any latency within the software being used.



The DMX USB Pro and DMX USB Pro Mk2 feature an internal frame buffer allowing them to output DMX at a constant refresh rate independently of the computer’s processor load. As soon as output values are updated in the computer, the Pro will update the buffer and output them as part of the next frame. If the universe is not updated, the USB Pro will continue to output the same frame again to ensure the refresh rate is maintained. The reason we do this is to ensure the frame rate is consistent and stable when you need it most. Given the huge number of processes going on a computer, relying on direct conversion it for a precisely timed data feed isn’t realistic.


Our Open DMX USB does not have an internal frame buffer or guaranteed consistent frame rate in the same way the DMX USB Pro models do. The Open DMX USB simply converts the DMX values into DMX frames 1:1 when the computer processor provides them. This is adequate for the majority of hobbyist applications where precise timing isn’t as important.

For professional applications, we recommend the DMX USB Pro or DMX USB Pro Mk2.