title: F# Performance Impact of Checked Calcs?
body: <p>Is there a performance impact from using the Checked module?  I've tested it out with sequences of type int and see no noticeable difference.  Sometimes the checked version is faster and sometimes unchecked is faster, but generally not by much.</p>
  
  <pre><code>Seq.initInfinite (fun x-&gt; x) |&gt; Seq.item 1000000000;;
  </code></pre>
  
  <blockquote>
  <pre><code>Real: 00:00:05.272, CPU: 00:00:05.272, GC gen0: 0, gen1: 0, gen2: 0
  val it : int = 1000000000
  </code></pre>
  </blockquote>
  
  <pre><code>open Checked
  
  Seq.initInfinite (fun x-&gt; x) |&gt; Seq.item 1000000000;;
  </code></pre>
  
  <blockquote>
  <pre><code>Real: 00:00:04.785, CPU: 00:00:04.773, GC gen0: 0, gen1: 0, gen2: 0
  val it : int = 1000000000
  </code></pre>
  </blockquote>
  
  <p>Basically I'm trying to figure out if there would be any downside to always opening Checked.  (I encountered an overflow that wasn't immediately obvious, so I'm now playing the role of the jilted lover who doesn't want another broken heart.)  The only non-contrived reason I can come up with for not always using Checked is if there were some performance hit, but I haven't seen one yet.</p>