Einar,

Timers are pretty efficient. They're basically a threading mechanism that fires off new threads (or threadpool threads really). If I remember right these timers are pretty close to underlying OS APIs so there's very little overhead for them, especially in low firing intervals as yours (many seconds).

Remember too that timers fire events on a separate thread, so they don't genearlly hold up the main app. Just make sure you keep the code in the handler simple and quick and if it's not to utilize Application.DoEvents() liberally.

+++ Rick ---

>I am creating a Windows service that uses a timer (System.Timers.Timer) to perform some tasks at specific intervals.
>In the OnStart of the Windows Service I create a new instance of my class:
>

>protected override void OnStart(string[] args)
>{
>  oMyClass = new MyClass();
>}
>

>
>In the constructor of MyClass I start a new timer
>

>public MyClass
>{
>  oTimer = new System.Timers.Timer();
>  oTimer.Elapsed += new System.Timers.ElapsedEventHandler(oTimer_Elapsed);
>  oTimer.Interval = 1000 * 25;
>  oTimer.Start();
>  oTimer_Elapsed(this,null);	
>}
>

>
>And now here comes the question: In addition to the things (thing#1) I want done every 25 seconds I also want some things (thing#2) done lets say every 100 seconds. Is there a lot of overhead accosiated with a timer object so that I should look into creating logic that does thing#2 every 4th time the timer fires (thing#1 is done) or should I add another timer with Interval = 1000 * 100 for thing#2?
>
>Please comment on any other parts of how I set up my windows service.
>
>Thanks,
>Einar