If the universe is a simulation, it would have to be on an analog computer which doesn't have a clock speed as such. Or a digital computer running sufficiently

If the universe is a simulation, it would have to be on an analog computer which doesn't have a clock speed as such. Or a digital computer running sufficiently tiny time steps to be indistinguishable from an analog computer. In either case I don't think c is directly related to "clock speed". I'm not a good enough physicist to tell you what it does mean. That's my feeling anyway.