Connection Queue Depth is a new parameter which defines how many outstanding I/O it can potentially have pending to the ISCSI Target SAN device. There are some limiting factors depending on the SAN vendor and what's negotiated. In testing we haven't found increasing this above 64 to really make much of a difference but can be increased for personal testing.
The parameters are as follows:
iscsinit reg set Connection Queue Depth=128 (Default: 64)
iscsinit reg list (will display the setting in the registry)