Sudden slowdowns on windows ( rev 4780 )

[titi]

This might be something similar as described by Coldfusionstorm but what I have are very sudden slowdowns. ( in case it matters here is Coldfusionstorms thread https://forum.megaglest.org/index.php?topic=9290.0 )

The Problem:
Suddenly in the middle of a ( multiplayer?) game the frames on windows drop a lot. You see frame drops from 80fps drop very suddenly to frames below 10 fps . So it is not a slow frame drop over time, it's more a switch from one second to another.

What we discovered so far:
- It only happens in multiplayer games ( Lan/Internet does not matter )
- it only happens on windows
- even very fast hardware is affected
- if the servers pauses/unpauses the game, The fps are back to normal. ( This shows it's clearly not load dependend, but must be a timing issue combined with thread trouble )
- it looks like this problem is relativly new ( I think rev r4682 did not had this problem )

( some revisions ago this was much worse than it is now, but it still happens , we did not saw it in 2 other games today, but our last one showed it )

[titi]

And here is a terminal´output that might help find the issue:

http://pastebin.com/raw.php?i=F8enpYMc

This happpened in the middle of the game and was "just" a drop down to 14 fps. after round about 30 seconds my son( server ) paused/unpaused the game and my windows game instantly was back to 80fps in this situation.

( update: mabye it started with this but I did not look at the console in this moment!: PERFORMANCE WARNINGS for World Frame: 18756 )