new hosts and storage all 10Gbit! Slower than expected file transfer?

[chazzy2501]

Hey I've got a new san and server combo. The 2 hosts are 2x10gbit each (lan) and the san is 4x 12gbit sas (2 to each host)

 

I've added the new 10gig adapters to the Lan vswitch and kept an 1gig adapter in setup as standby. I've done a crystaldiskmark on the vms and the speed is amazing at over 3000MB/s

 

I was testing file transfer by sending a 12GB ISO via SMB from one VM to the other but the transfer caps out at 1.6Gbit?

 

is this expected, what should I look for?