C# process standard output delay

Question

From a C# form I am running a process with start info similar to Redirect console output to textbox in separate program and C# get process output while running, the process

Answer 1

The buffering happens on console program end. By default, stdout is fully buffered if known to be redirected:

If stdout is known to not refer to an interactive device, the stream is fully buffered. Otherwise, it is library-dependent whether the stream is line buffered or not buffered by default (see setvbuf). Source

So, unless you can alter the console program source to disable buffering, nothing can be done on GUI program side.