How to run fme.exe?

Actually, there is not much of a difference. On both occasions I run the same workspace. Running it via cmd.exe the working directory is located at the location of the workspace, while starting it in fme.exe through my C# application the working directory is within the applications directory. Just at one point something that takes only seconds when running it via cmd.exe,

2021-10-28 11:08:17|  3.2| 0.0|INFORM|Matcher (MatchingFactory): Splitting bulk features into individual features
 
2021-10-28 11:08:18|  3.2| 0.0|INFORM|object_kommune_intersect_m_timezone_SQLExecutor_3 (QueryFactory): 22 input initiators processed
 
2021-10-28 11:08:18|  3.2| 0.0|INFORM|object_kommune_intersect_m_timezone_SQLExecutor (QueryFactory): 22 input initiators processed
 
2021-10-28 11:08:18|  3.2| 0.0|INFORM|PGVInit_med_kommunevalg_SQLExecutor (QueryFactory): 22 input initiators processed

takes about 10 minutes when running directly in fme.exe

2021-10-28 12:16:12|  3.1| 0.0|INFORM|Matcher (MatchingFactory): Splitting bulk features into individual features
 
2021-10-28 12:26:07|  4.8| 1.7|INFORM|PGVInit_med_kommunevalg_SQLExecutor (QueryFactory): Processed 35 of 47 features

Thereafter, it goes relatively smoothly further and takes about the same time, independent on how I execute the workspace.

I have coded some apps to achieve the same as you and I haven't noticed any impact in performance.

This is my code in case it helps:

string strCmdText  = '"' + [path_to_workspace] + '"';
 Process process = new Process();
 process.StartInfo.FileName = [path_to_fme.exe]
 process.StartInfo.Arguments = strCmdText;
 process.StartInfo.UseShellExecute = false;
 process.StartInfo.RedirectStandardOutput = true;
 process.StartInfo.RedirectStandardError = true;
 process.Start();
 
 string output = process.StandardOutput.ReadToEnd();
 string err = process.StandardError.ReadToEnd();
 process.WaitForExit();

string strCmdText  = '"' + [path_to_workspace] + '"';
 Process process = new Process();
 process.StartInfo.FileName = [path_to_fme.exe]
 process.StartInfo.Arguments = strCmdText;
 process.StartInfo.UseShellExecute = false;
 process.StartInfo.RedirectStandardOutput = true;
 process.StartInfo.RedirectStandardError = true;
 process.Start();
 
 string output = process.StandardOutput.ReadToEnd();
 string err = process.StandardError.ReadToEnd();
 process.WaitForExit();

Thanks, doesn't look promising, but reassuring... I am doing exactly what you are doing @oscard​ 

ProcessStartInfo startInfo = new ProcessStartInfo()
            {
                FileName = fmeExe,
                UseShellExecute = false,
                RedirectStandardError = true,
                RedirectStandardOutput = true
            };
 
string arguments =
                    $"{scriptName} " +
                    $"--kommune \"{SelectedMunicipality.Code}\" " +
                    $"--geodb \"C:\\Temp{output}.gdb.zip\" " +
                    $"--user \"{user}\"";
 
 using (Process process = Process.Start(startInfo))
                {
                    if (process == null) return;
                    try
                    {
                        //get FmeScript from collection to update values
                        FmeScript fmw = FmeScripts.FirstOrDefault(x => x.FmwPath == startInfo.Arguments.Split(new[] { ' ' }, 2)[0]);
                        fmw.ProcessStart = process.StartTime;
                        process.ErrorDataReceived += process_ErrorDataReceived;
                        process.BeginErrorReadLine();
                        process.WaitForExit(600000);
                        if (process.HasExited)
                        {
                            fmw.ProcessEnd = process.ExitTime;
                            fmw.Status = _status == null ? "succesfuld" : _status;
                            await AddScriptToTable(fmw, user, taskId, fmeVersion);
                            _status = null;
                        }
                    }
                    catch (Exception e)
                    {
                        Console.WriteLine(e);
                        throw;
                    }
                }