Another update:

The previous tests were made with the target configured in File I/O mode with WB enabled.
I ran test with WB disable, also in the controller WB was disabled but the performance was too slow.

Recently i have configured the DSS V6 Lite with Block I/O with WB enabled. Now i have a better performance but it still slow.

Esxi says that the nics are transmitting about 30.000 Kbps each.

What other test I can do to figure out what is the problem?

Thanks!