I use a multisite installation on my own virtual server.

Hi,

I use a multisite installation on my own virtual server. The problem is site loading times. My site is very, very, very slow. I have tried stripping it down from plugins and the sites theme is coded by an elite author at themeforest.net. I use a ssl wildcard certificate which also slows the site? I have tried configuron WP Super Cache but the loadtimes are still very poor. Could I have use of switching my server to WPPronto or something else? I´m located in Finland (Europe) so switching to a USA hosting provider could slow things down even more? Or?