Event Store slows down after about 1 million appends to 30,000 streams

I tried migrating my database to the event store and when I was importing my data I faced this issue that after a number of writes, the db slows down on write operations

I Use Event Store with a .net client
My storage is SSD
My events are smaller than 15MB
It is a single instance and not replicated
please let me know if additional detail is required

my machines resources don’t even get fully or half way consumed CPU, RAM or storage

Hi erfanviva,

You mentioning the events being smaller than 15 MB caught my eye. To me, even 1 MB for an event is incredibly, fantastically large. Usually, events (even outside of EventStoreDB) are small and include the delta (difference) in a state change for something. If you’re appending such large events, I would expect there to be a slowdown.

What would you say is the average size of an event?
Were you storing these events similarly in your previous event store? May I ask what you were using for persistence?

EDIT: I realized after I posted this, you likely are referring to your entire event store storage size being less than 15 MB. Oops! If you could please clarify that would be appreciated.