News from the HP Support, they think that the Quad Nics NC 364T are not supported for the DL 380 G7 Server series... ha ha ha... On the production page of HP there is a compatibily list and look at this -> HP Product Bulletin -> HP ProLiant DL380 G7... uuups !!!
From the VMware Support we get the answer to our call, that maybe the Software iSCSI HBA is the problem, and with that use VMs are limited to an IOps of 4000. They told us to use a real Hardware iSCSI HBA. Dear VMware Support, the DL380 G7 has 4 Broadcom OnBoard Nics which are shown as HW iSCSI HBA in the vSphere Client, and no one can tell use how to use them as Hardware iSCSI.... so now ???