I remove the heat sink, and the thermal pad don't do a good contact with two memory chip :
http://img405.imageshack.us/img405/3...ercooling2.jpg

I apply thermal paste on the vrm and on the chip which don't do a good contact.

Now the temperatures are realy better :

The vrm don't go over 80°C on OCCT without any airflow ( vs 100°C with antec tricool set to high) but the gpu temp 2 continue to go to 80°C.
I hoped that the GPU temp 2 where the ram chip who don't do a good contact but apparently not