There is a general problem when demand allocation of real hardware resources cause variability in the behavior of programs. Designs of such allocation mechanisms aspire to be invisible to the program requring the resources and indeed largely suceede in this to the degree that facilities designed to yield stable results do so in the presence of these unanticipated allocations and deallocations. In other words programs that wish to be fooled are well fooled.
Some programs want not to be deterministic. Programs require a source of noise (entropy) to produce a crypto key. Programs want to do Monte Carlo calculations, but these are generally better off with pseudo random numbers. Some programs want to sense the allocation of real hardware resources for purposes of performance analysis, or for more sinister purposes of receiving data transmitted over a covert channel.
A program that is deciphering your speech has no need to read the microsecond clock. It needs to know when the signal was spoken, but not what time it is now. If it has the extra plan to steal your secrets, it may well read that clock in order to gain information on other demands on the allocated resource, and draw conclusions about