Problem of saturation of ram on XNA?

Question

I developed a small xna games. For some time I have a problem with the saturation of RAM. In fact everything works perfectly, the game runs with a "Frame" of 60fps. But strangely I do not know for what reason my games every 4 seconds freeze half a second.

Yet my average call time of the "Update" function is approximately 7 ms (which is supposed to be good ..)

Here is a screen capture of the Task Manager. I can see the ram flush periodically.

Have you any idea why the ram saturates at only 50%?

Answer 1

This is probably due to the Garbage Collection kicking in every x seconds. In general, you should minimize (or even eliminate) creating "garbage" in an XNA game. Examples of things that could create garbage during the game loop:

• Calling anonymous methods or closures.
• Setting/clearing delegates or event handlers.
• Using an enum as a key in a dictionary. Simply doing a lookup creates garbage in this case.
• Pretty much any string manipulation. For example, doing "silly" things like wanting to create strings using "+" or "string.Format, etc.
• Adding/removing items out of a LinkedList. It is very common to have objects added/removed from linked lists in the game loop. So now you have to roll your own linked list, or use something other than linked lists.
• Accessing value types via an interface will cause them to be boxed (Is this really true? I was not aware of this).
• Some enumerators create garbage. Good luck figuring out which ones do and which ones don't. Quick: Does foreach() on a Dictionary ValuePair create garbage? Often it seems safer just to fall back to for() if you are unsure (where the collection allows this).
• Using yield in order to enumerate objects.
• Calling List.AddRange(), even if there is sufficient capacity to hold all items.

(Source: Channel9.MSDN.com)

As for best practices, here's a very nice collection of articles.