Help for APACHE configuration

Hi,
I've a apche server (with also MySQL installed) witch manager 200 Mambo
Sites and 250 MySQL Db.

My HArdware is
2x Xeon 2,2Ghz (DualCore)
2,5 Gb RAM
HDD SCSI360

How can I optimize the performance of my apache configuration?
My server sometime crash and after I reboot the services everything goes
right.

Could be a good Idea to move apache service in another Server?
Thanks for your help!