Actually, the system where I tested to 1000 simulated users was fairly moderate. 2 web servers and one database server. All VMs. I can't remember how many cores or RAM, but it was not excessive.
We did use Postgres database, which has always been good at simultaneous writes. I am not sure how good MySQL is in comparison. Probably better these days than in the past.
Anyway, if you get some numbers for what your hardware can do, I will be very interested to see them.