Process.start is slow compared to Powershell Start-Process RRS feed

  • Question

  • I wrote a command line program to create a process and run a simulation in the background. This worked fine for many years but IT pushed something to our computers and it no longer works efficiently.  I use this program to start 200+ simulation runs and as they queued up, they would use 100% loading all my workstation 40 cores until they finished in about 15 seconds. I am not sure what IT pushed to our computers but now I can only get about a 30% usage of my cores and takes 45 seconds to complete.  The program only gets about 12 or so simulations running simultaneously.  So I tried using Start-Process in powershell and low and behold, it would queue up enough simulations to run to load all 40 cores to 100%.  Can anyone tell my how I can get the Process.start to use all of the processing power.  IT does not know what has changed to cause the issue.  It is a policy setting as IT did test a clean computer without the required policy settings and the Process.Start was able to load all of the cores.

    Here is the code I used to start running a single process in C#.

              Process process = new Process();
              if (optionHidden)
                process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
              process.StartInfo.FileName = application;
              process.StartInfo.Arguments = arguments;
              if (optionWait)
            catch (Exception e)
              Console.WriteLine("Failed to launch {0} because of {1}", application, e.Message);

    The application name is nStart and looks like this to start all of the simulation runs.

    nStart /hidden nDOF.exe MM0000.ndof
    nStart /hidden nDOF.exe MM0001.ndof
    nStart /hidden nDOF.exe MM0002.ndof
    nStart /hidden nDOF.exe MM0003.ndof



    The powershell script looks like this.

    Start-Process .\nDOF.exe  -ArgumentList 'MM0000.ndof'
    Start-Process .\nDOF.exe  -ArgumentList 'MM0001.ndof'
    Start-Process .\nDOF.exe  -ArgumentList 'MM0002.ndof'
    Start-Process .\nDOF.exe  -ArgumentList 'MM0003.ndof'




    Wednesday, April 18, 2018 5:17 PM

All replies

  • Is any impact if you set ‘process.StartInfo.UseShellExecute = false’?

    Wednesday, April 18, 2018 7:02 PM
  • Thanks for the idea.

    I just tried it and there was no difference. I also tried "start" in a Command Prompt and that started each simulation fast enough to load the overall CPU to 100%.  I am guessing there is some sore of StartInfo parameter I need to set but I have not successfully figured out what that parameter may be.

    Wednesday, April 18, 2018 8:34 PM
  • Hello conrarn,

    Maybe you could check the below document.


    Best Regards,

    Neil Hu

    MSDN Community Support
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    Monday, April 23, 2018 9:57 AM