OK, thanks for your help. So just a quick summary what speeds up my game again.
I have downloaded the process monitor. Started it before playing sims. Just one filter for "Paths" which ends with .package. Then starting the game, playing for 10 minutes. Then back to the monitor. There were about 21000000 package files loaded.
So i tried file summary from the menu, and there were just 4 files which were opened about 20000 times during these 10 minutes of play. So i deleted these 4 files from my CC, deleted the cache files and the game is running like hell again.
Here is the link for all who need this monitor. http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx
So u dont have to read all related articles if u want to get your speed back.