Since 1993!
Ive been a Cubase user since 93, when all we had was MIDI, and if you were wealthy a Roland SCC-1 internal MIDI interface / soundcard. When VST became a reality our systems cost a ridiculous amount, and even then the bottlenecks were harsh. Technology growth with audio has amazed me and the dedication of the programmers at Steinberg really should be awarded some sort of thanks, incredible advances, so for what its worth, I thank you.