Is the digest calculated in production environment for russian doll caching?

Question

I have made some measurements regarding the russian doll caching.

The fragment of view is:

<% b = Benchmark.measure do %>
  <% cache_if m.persisted?, m do %>
    <% puts '...Cache Invalidated. So Regenarated...' %>
    <div class="row meeting-top">...
    ...

  <% end -%>
<% end -%>

<% puts '-------------------------------' %>
<% puts 'Caching time:' %>
<% puts b %>
<% puts '-------------------------------' %>

With cold cache the view is generated in 4.1 sec:

Caching time: 1.500000 1.540000 3.040000 ( 4.105240) ...Cache Invalidated. So Regenarated... Rendered meetings/_meeting_details.html.erb (4108.2ms)

With warm cache the cache is read in 1.8 ms according to the log, but the measurement shows 1.4 secs: Read fragment views/meetings/175-20161107081414758395000/a11719fdb839d5d56266b0a96091dfb0 (1.2ms)

Caching time: 0.520000 0.640000 1.160000 ( 1.420288) Rendered meetings/_meeting_details.html.erb (1426.6ms)

This means that the russian doll digest tree for the cached views is calculated in 1.4 secs. Is the same digest tree calculated in production environment? If not then can I expect that in production everything will be faster with 1.5 secs?