So my client asked me to provide a rough estimate of a number of CPU cores and the needed memory for a specific project I'm working on. But the project is complex, is different from anything I've been working on and different from anything they have running, is not completely defined yet and not much has been done.
I only have an idea of the applications, tools and databases that will be involved in the architecture, some estimates of the numbers of requests by seconds on the system, and some unoptimized proof of concepts of some of the applications.
I told my client that I couldn't yet and that we had to wait until we had some parts of the system running to do some load testing and then decide.
But I'm wondering if there is any method that I don't know to go about this?