ssd access freeze windows 7/8

i had corsair force 128GB on my macbook pro. i installed mac os and windows 7 as bootcamp. i had no problem except disk space. i bought neutron 256gb. i have problems on windows 7. it is like it freeze on disk access. so windows 7 is so slow. i wait for seconds to open a windows. mac os works well like on corsair force. i have also parallels. i can run the same windows 7 in parallels well. it is fast. i installed the latest bootcamp drivers. now i upgraded window 7 to window 8: i have the same problem. what can i do?