Architecture question

We have Netbackup 7.5 Standard installed on windows 2008 R2 on a single combined Master/Media server.  Our backup pool is an iSCSI attached device called StorSimple.  We have created 5 drives which we mapped to 5 storage units. 

We are backing up 5 servers, with about 4 million files per server.  The size of each server is between 3 and 10 TB.  We have 1Gbe connection between the Master/Media server and each of clients/servers.  Our nightly backup window is 12 hours.

My question is this single server design supposed to be able to handle the work load that we are asking of it? 

Thanks

Mike