Performance issues with Get-Mailbox -Database PowerShell cmdlet

Hello,

I have a database with say around 5000 users. My below non-fancy cmdlet takes close to 4 mins for getting the mailbox objects. Is there a way I can speed it up?

Get-Mailbox -Database -resultsize unlimited

I would love to bring this down to less than 2 minutes if possible. I have tried with result sets of 1K and smaller, but that doesn't help.

I thought about doing an LDAP query instead on relying on Exchange cmdlet, but looks archiveName property is not stored in AD and my application needs that property.

By the way, I have three databases in my environment with around 8K users, if I run the cmdlet concurrently, it hogs up whole of my cpu and takes close to 7 minute.

Thanks