title: Inconsistent intervals with System.Windows.Forms.Timer
body: <p>Please be kind, I'm just learning C# and inheriting this application from a former-employee is my first C# project.</p>
  
  <p>I am observing inconsistent and slow periods with System.Windows.Forms.Timer.  The application is written in C# with MS Visual Studio.</p>
  
  <p>The timer is set for an interval of 100 msec yet I am observing periods ranging from 110 msec to 180 msec.  </p>
  
  <p>I am using several tools to observe this including:
  - a SW oscilloscope (the Iocomp.Instrumentation.Plotting.Plot package), 
  - a real oscilloscope, 
  - letting the timer run for some time and comparing the number of ticks * 100 msec to both the system time and to a stopwatch.  </p>
  
  <p>In all cases I am observing a 10% lag that becomes evident within the first few seconds.</p>
  
  <p>The methods that are executed with each tick take fewer than 4 msec to run.  There is no time-consuming asynchronous processing happening, either.  This shouldn't matter, though, as the timer tick is an interrupt, not an event added to an event handler queue (as far as I know). </p>
  
  <p>Has anyone experienced a problem like this before?  What were the root causes?</p>
  
  <p>Thanks.</p>