Redis w/ HHVM on wordpress - slow first load

I have a site that isn’t highly frequented. In my tests it seems that the first visit after a period is 3seconds and subsequent visits are 1.2seconds or less. I’m curious if this is just the cache was dumped from before and it is loading again for the “first visit”. If this is the case, is there any way I can preload the cache?

Is this an issue I should even concern myself with?

New to all of this, just getting into it.

Thank you

Bescause hhvm decode php to C, it costs resources and time.