Many archived mailbox and impact on performance?

Hi All,

I have EV11 upgradated step by step from 8 version (as I remember)

Users incoming to company, archiving data, and leave from company. Archived mail stay. After few years I have a lot of archives without users (stay sids with archive display)

Actually I have 40TB data.

Question is How many this archives can be on one EV store ? Where is the border after which performance will be low, or lowest if I will be delteted this archives with sids from EV console?

I was reading performance guide for EV11 but not found information about this.

Regards.