CPU utilization is very high while running SAP backup through RMAN

Hi all

We are running backup of SAP server through Networker module for SAP.While running the backup through BR tools by calling backint, the CPU utilization reaches up to 30 to 40 %. However if we run the backup through Brbackup by calling RMAN utility, the CPU utilization reaches up to 90 to 95 %. The oracle.exe process consumes most of the cpu resource at the time of backup through rman utility.Can anyone faced this problem before and have some resolution ?