Hi Jeon Min,
Can you help me to understand your question better?
Are you asking for the normal expected boot time for each of these models? Is this for planning time for an upgrade?
Boot time for EXOS products is dependent on several things, namely CPU capabilities and configuration. The more configuration and ACLs, the longer it could take to fully boot and become operational.
The two BD8800 modules that you have mentioned are part of a chassis and their boot time is dependent on total system status.