Process.Start() significantly slower than executing in console

Question

I have performance problems executing an .exe using `Process.Start()`. The execution takes roughly 5 times longer from .NET then it does from console. What can cause this? Here is a test program: ``` public static void Main(string[] argv) { for (int i = 0; i < 10; i++) { ProcessStartInfo psi = new ProcessStartInfo(ExePath, Args); Process ps = new Process {StartInfo = psi}; Stopwatch sw = Stopwatch.StartNew(); ps.Start(); ps.WaitForExit(); sw.Stop(); Console.WriteLine(i+" Elapsed time: " + sw.ElapsedMilliseconds + "ms."); Thread.Sleep(1000); } } ``` The result is this: ``` 0 Elapsed time 4310ms. 1 Elapsed time 4330ms. 2 Elapsed time 4280ms. ... ``` Running it in a cmd window returns almost immediately (sub 1 second execution). Tried timing it in the console using ``` > powershell Measure-Command { cmd /c start /wait %EXE% %ARGS% } ``` Which shows around 750ms for the execution, which is a good 5-6 times faster. Not sure I did that right, but 750ms feels like a likely execution time. At…

Accepted Answer

The difference in running time in this case was due to different versions of the executed (`racer.exe`) file, and had nothing to do with the fact that one was being executed from a .NET process and the other from the command line.

There shouldn't be a difference when running an executable from .NET as it is simply using system calls to execute the program.

Process.Start() significantly slower than executing in console

Solution

Problem