That was actually a big problem with PS2 emulation - some parts of the system were hardcoded to wait only a certain amount of time for a function to finish - because that function was ran on a different chip, and would always take the same amount of time. Now emulating that behaviour was incredibly difficult, especially if all of it had to run on a single CPU. The problem has been mitigated somewhat by multi-core CPUs,with each core emulating a different part of the PS2, but it's still far from ideal.