Average Job Rate when backuping VMs using SAN Transport Mode

Hi,

We have setup a Lan free backup environment for our VMs (VMware).

What is the average job rate(optimum or godd)?. We are getting around 2500 MB/minute.

Also when ever we initiate a job there are some hundred tasks like 'Mapping disk region and Releasing disk region' is  in running in our V-Center . Is this normal in a SAN based backup environment?