Hyper-V Virtual Machine accessing a SAN

Hi, I have a Dell PowerVault MD3200i and I am having an issue with data transfer speed from a virtual machine to the SAN. I have the host configured with multiple connections to the SAN via private NICs and it transfers data to the SAN quickly. I configured a VM on the same machine using multiple virtual NICs to the same private subnets of the SAN and it connects fine; however, the data transfer speed is probably a tenth of what the host is pushing. Any thoughts? The host and the VM are both Windows 2012 R2. Thanks for your advice.