My team asked me what is the CPU cores and memory requirements to run a 1000 or more rUsers test?
This is a hard question because CPU, Memory, and hard drive/SSD vary in performance depending on your application, but it should be in this ballpark:
12-Core/24 GB RAM / 80 GB HD per 100 rUsers (X10 Injectors), or one c5.24xlarge VM from AWS can handle 1000 rUsers.
To know for sure, you need to run a test on 1 injector, adding users until it no longer can run the test (it will be obvious and immediate). Once you know the max for one server, you can then calculate how many are needed for 1000 users. Cloning and adding new VMs then becomes an easy task. (eg: if one injector can handle 100 users, then you need 9 more with the same configuration.