I would like to update this issue.
I did some additionnal test :
If i put my HDD RDM to one VM -> 150MB/s
====> ESX driver is not good for my storage controller ?
I have Intel cougar 6
Is there one solution to improve performance without use RDM disk ?
Then, I would like to know if I buy a Supermicro motherboard X8XXX (1366 socket) :
VMware SAS driver will be good ? storage driver ? Or I can have the same issue and slow disk performance ?