このスレによると、ソフトウエアでファン制御すると静かになるぽいね。

Download NoteBook FanControl (http://www.computerbase.de/forum/showthread.php?t=1070494)
from here. After you'e downloaded it and set it up, select the Sony Vaio E series fan configuration
(it uses the same configuration as the T series).

http://community.sony.com/t5/VAIO-Hardware-Networking/Vaio-T-Series-CPU-fan-way-too-loud/td-p/26976/page/2