om/greg7mdp/parallel-hashmap/blob/master/img/stl_flat_both.PNG?raw=true" alt="stl_flat comparison" /></p>
<p>On the bottom graph, we can see that, as expected, the Abseil <em>flat_hash_map</em> is significantly faster that the default stl implementation, typically about three times faster.</p>
<h3 id="the-peak-memory-usage-issue">The peak memory usage issue</h3>
<p>The top graph shown the memory usage for both tables.</p>
<p>I used a separate thread to monitor the memory usage, which allows to track the inc