Swap memory over 2GB used, but oddly the physical memory is only about 50-75% used, shouldn't it put all the memory into cache? I see a bunch of apache processes about 98M each.

Something like this:
Size: 98M
RSS: 7000
Share: 7000

I also see some other 98M processes something like this:
Size: 98M
RSS: 95231
Share: 45011

I know RSS means how much physical memory that process is using, but what about size and share? What do they mean technically?

In the past I have this problem before and turned off output buffering, but it is already turned off and I still have these problems. Are there any configurations I could tweak? httpd.conf php.ini my.cnf and what should be tweaked?