Can someone provide references / guidelines on how much server (memory/CPU) an installation of vanilla PHP would require for a given workload ?
I've been looking at the Amazon EC2 instance sizes http://aws.amazon.com/ec2/#instance and it made me realise that I don't really know how much hardware you need to serve X pages/hour using PHP.
I realise of course this is heavily dependent upon what the page is doing but I'd be interested to see any numbers which give some guidance on how much you can expect from a given machine setup (and maybe some of those smaller setups wouldn't even allow PHP to start ?)
My assumptions would be - only PHP+nginx on machine (no database) until the workload reaches a point where some caching in front of PHP would actually allow for a smaller machine for a given workload than would otherwise be the case.