When did Linux/x86 overtake proprietary Unix/RISC?

For those of you working in the late 80s and early 90s, when was the moment and context when you realized that Linux on commodity x86 hardware was faster/better value than the proprietary Unix and RISC boxes you were using? And how did you use that knowledge? And I'm not knocking too hard on the excellent tank-like hardware and great build quality of the expensive stuff, but when you saw the speed of Linux/x86 and realized what you could get at that cost, it must have been a huge shift in your thinking, and I just want to know more about that particular time.