until y close the windows "Even Log" during a debug session.
Probably a coincidence. But you can re-open it...
Likely causes:
Maybe your app has a lot of exceptions? You would have them on the ignore list, but the debugger has to check the type of exception each time. So each exception hit will cause a small delay.
Or you have conditional breakpoints, (check menu > view > debug windows > breakpoints). They still stop to check the conditions.
(Same with breakpoints that have the "break" option disabled, but may do other work)
You could try disabling all breakpoints and test....
If it is one of those, options are limited
1) try fpdebug. (package LazDebuggerFp / Tools > Options > Debugger / search wiki)
It still has the same limits as above, but may take less time.
2) In Lazurus svn trunk, the gdb based debugger has an option (in the property grid / Tools > Options)
InternalExceptionBreakPoints => Disable at least ieRaiseBreakpoint (you can disable all).
However then the debugger will never stop at any exception.
If neither of the above is the case then probably more info is needed.
Does the slowdown occur while the app is starting? Or is it during the entire lifetime of the app?
For "app is starting", it might be loading dll taking more time. (Of course that can happen at any time, if your code uses LoadLibrary a hell of a lot)
In that case (if using the gdb based debugger), find the option
DisableLoadSymbolForLibraries and set it to true.
You can do that in any case, unless you write your own dll, and want to debug your own dll.