I am a newbie here, please let me know if I'm using wrong webmaster terms.
I am currently setting up a VPS for a multi site WordPress. The VPS uses Debian 6 LNMP setup and the DNS is being taken care by another service. Currently the VPS is running non multi site WordPress with -+ 83 MB RAM out of 128MB. As far as I know the performance is relative to the number of request, not the number of sites in the multi site setup.
How do I calculate maximum number of request in with that setup? If the information is not enough, what other factor do I need to know?
Thank you in advance.