As stated, if you intend receiving a serious response, try asking in another forum like JEE or Distributed Computing.
Personally I believe most of the performance issues are based on the amount of data and additional resources (css, images, JS etc). Also, it is well known that databases are black holes of performance. Best to do without them all.
1. Try to keep pages down to a few words at most. Ignore HTML standards and do not allow creative input. 2. Do without database or any external storage mechanism. There was an Java Object DB that kept everything in-memory and it was blisteringly fast. It took forever to startup and shutdown and required about 28Gb of ram, but they are solutions, not problems 3. Try to keep all data static and make the client cache everything.
The biggest drain on you machine performance, however, are users. If you design the site to minimise unique visits, resources will never be an issue. Your job will be safe and no one will criticise the application performance.
As an additional tweak, when running internal demonstarations for bosses and shareholders, evict all external users, reset the system and block external traffic.