"The basic advice regarding response times has been about the same for thirty years :
0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result."
Originally you asked "is 54.55 ms perceptable?", I say yes. I can tell the difference between 25 ms and 1 ms in my terminal.
That said, I don't think it is worth trying to reduce your startup time to the point where you can't tell the computer took time. Getting "the user [to] feel that the system is reacting instantaneously" is a different and more important goal.
0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result."
https://www.nngroup.com/articles/response-times-3-important-...