my server has 2xCPU + 48GB ram. and I stream like 20K
20k real-time watchers on 1 server will make bottleneck effect.
Not really. Depends on the uplink But i assume he has atleast 20Gbps connection at that server otherwise is an bullshit
But how HDD or SSD will provide more than 2gbps ? I have the same problem so i separate my files on 3 different servers with 5gbps and now can handle much more traffic.