I'm only testing with 1 nic as it also should be able to give 900mbit performance on the vmware enviroment.
Though I tried making 2 vmkernel NICs with different IP's on the same vswitch and bound them to iSCSI... then enabled Round-robin.
Has made no difference.
I don't think that the issue is related to load balancing tasks, but rather a communication issue between the vmware and the lefthand. The storage works perfectly when testet on a Windows 2008 server using MS iSCSI Initiator.
So it should be software related like a driver problem, misconfiguration or missing iSCSI tweaks. I just don't have a clue where the problem is.