System loading very slow after adding 3000 clients

[mgrWetales]

I have imported 3000 plus clients with their contacts.
Now, this system loads very slow and in the debugger, it shows 3092 queries with 6523 models loaded.
I checked server resources and found MySQL is taking 50% plus memory on each request.

[Bottelet]

I see. thank you. I will try and make some performance optimization, I haven't really focused on this, at any point.