The only way to improve it is cache it for maybe x minutes, and then update cache. Maybe you should provide the reason why it can't be cached for say maybe 5 m

The only way to improve it is cache it for maybe x minutes, and then update cache. Maybe you should provide the reason why it can't be cached for say maybe 5 minutes. If its a problem where they are reloading, the homepage to see results then you could do incremental updates of each section using comet technique.