[resolved] FPS are going down during the first minutes

[mimydestroy]

Hello everyone, and thank you for your help on dolphin emulator !
here is my probleme :
I played now 2 games on many version of dolphin (2.0 and last revisions) with many configurations I found on help pages and other forums on internet, and the probleme is always de same :
the game is playing fast during the first 10 second, and after encounters some FPS degradations, FPS are going down constantly. after 2 minutes, the game plays around 14fps everywhere...

Here is my configuration :
Vista 64
GTX 275
Q9950 2.83ghz
4094 Mo

thank you again for your help.