Hi,
Virtual channels have a similar memory overhead to real channels, as a virtual channel’s underlying DSP units and the sample data being played are still present in memory. However, the CPU overhead is significantly lower for virtual channels than it is for real channels. This is because when a channel becomes virtual, the channel’s underlying DSPs become idle - while the DSP clocks continue to increment, the DSPs no longer process and generate an output, which saves on CPU usage. DSP units that have a tail (i.e. reverb, delay) receive no input since their input is idle, and will keep processing until the tail finishes and then become idle.