Plesk low ram server usage

I’m hosting websites on Plesk with: memcached + eaccelerator + apache deflate + apache cache + reverse nginx + php cgid <br> <br>Is it possible to keep running this server with 100 or more websites without lag?

My semi-qualified guess would be yes, if… <br>- you got rid of plesk <br>- replaced apache and php cgid with nginx and php-fpm <br>- used nginx built in cache mechanism to replace memcache <br>- use redis server <br>- traffic is anonymous <br>- shared code base as in all 100 sites running of the same wordpress core. <br> <br>100 websites with 100 anonymous unique visitors per day is only 10K hits which I doubt would be concurrent. But if most of the conditions suggested above are not met, I would say you’d require double the cpu and mem.

Now I’m running 8 GB ram with 4 cores. Server configuration is the same. So about how many websites I could host?