Hello Genzy,
The Gaia forum uses Memcache system + Cluster for the server. I think the server for the forum is more than 70 servers. Memcache system uses RAM for temporary storage for recent data. Of course, RAM read/write speed is very very very very fast compared to HDD.
A dedicated server won't be sufficient for Gaia
However, for webmastermalaysia.com forum, a proper setup server should be enough.
Thank you,