title: Parallel reduction example
body: <p>I found <a href="http://code.google.com/p/stanford-cs193g-sp2010/source/browse/trunk/tutorials/sum_reduction.cu" rel="nofollow">this</a> parallel reduction code from Stanford which uses shared memory. </p>
  
  <p>The code is an example of 1&lt;&lt;18 number of elements which is equal to 262144 and gets correct results. </p>
  
  <p>Why for certain number of elements I get the correct results and for other number of elements, like 200000 or 25000 I get different results from what is to be expected?
  It looks to me it's always appointing the needed thread blocks</p>