Copying data from Virtual Machine Disk to Local disk is toooooo slow

We have recently implemented vMware visualization.   We have vSphere 5.5 and View 5.2 and done server & desktop visualization.

We have SAN as HP 3Par and Esxi hosts are HP ProLiant DL380p Gen8

Now while trying to copy data from the virtual machine disk to local machine disk is too slow. But if we are writing data from Local disk to virtual machine disk is normal. And copying data between two virtual machine's disk is also fast.

Thanks in advance for your help