Copy VM from ESXI 5 to ESXI 5 is slow

Hi, I try to copy VM1 from ESXI 5 to ESXI 5 with ovftool by run ovftool -ds=datastore1 vi://root@10.0.0.1/vm1 vi://root@10.0.0.2 on WIN7 cmd. (WIN7 is vm on destination server where I whant to transfer vm1)

VM have 43GB used. I have two servers with those ESXI5 connected by 1Gbps network.

The issue is that transfer is very slow. I can get proximetly 30Mbps.

How can I make it faster? I run that four hours and still was not completed.

Thanks for advice!