title: Issue with download speed with DownloadOperation
body: <p>I have an UWP (Universal Windows Platform) application on Windows Store and this application is nothing but an audio/video downloader on internet with my <code>DownloadOperation</code> class.</p>
  
  <p><code>DownloadOperation</code> speed is very slow regardless of internet speed.</p>
  
  <p>When the audio/video size is less than average of 5MB then the speed of downloading is very slow compared to file size greater then 30-40 MB. But the overall speed of my downloading is in Kilobytes per second.</p>
  
  <p>I notice this download speed from task manager application sometimes and sometimes using my network tools. Tried using <code>HttpClient</code> instead of <code>DownloadOperation</code> but that doesn't produce any difference in my case.</p>
  
  <p>Example Code : </p>
  
  <pre><code>        string source =
              @"https://r1---sn-nv47lnes.googlevideo.com/videoplayback?id=o-AF3ULlrgm4d4p8IDGAzJbL8LUsQ7xOkiD5zYJAiTJGTT&amp;mv=m&amp;mt=1531996353&amp;ms=au,onr&amp;mn=sn-nv47lnes,sn-4g5ednly&amp;mm=31,26&amp;ip=213.14.6.130&amp;pl=22&amp;itag=17&amp;gir=yes&amp;requiressl=yes&amp;initcwndbps=493750&amp;source=youtube&amp;ei=K2lQW4uRNYyRgAOi7rPYDA&amp;lmt=1385600724132940&amp;sparams=clen,dur,ei,gir,id,initcwndbps,ip,ipbits,itag,lmt,mime,mm,mn,ms,mv,pl,requiressl,source,expire&amp;ipbits=0&amp;fexp=23709359,23745105&amp;fvip=1&amp;clen=2754619&amp;dur=268.329&amp;c=WEB&amp;key=yt6&amp;mime=video/3gpp&amp;expire=1532018060&amp;signature=9DB761B443EAB96C65E69BAF1A3923D9E64093C4.4AAF9E5E8CA43E0426D59ECFFF9D84638AA8DD81&amp;ratebypass=yes";
          StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync("omansak.mp4", CreationCollisionOption.GenerateUniqueName);
          BackgroundDownloader backgroundDownloader = new BackgroundDownloader();
          DownloadOperation downloadOperation = backgroundDownloader.CreateDownload(new Uri(source), file);
          await downloadOperation.StartAsync().AsTask(new Progress&lt;DownloadOperation&gt;(operation =&gt;
          {
              BackgroundDownloadProgress currentProgress = downloadOperation.Progress;
              if (currentProgress.TotalBytesToReceive &gt; 0)
              {
                  var percent = (int)(currentProgress.BytesReceived * 100 / currentProgress.TotalBytesToReceive);
                  button1.Content = percent.ToString() + "-" + currentProgress.TotalBytesToReceive.ToString();
              }
  
          }));
  </code></pre>
  
  <p>For example , this download code take 40 sec wirh DownloadOperation but normally avg 3sec . 
  How to use maximum network (i.e., maximum speed of internet) while downloading file?</p>