Anyone know whats the different between the physcial momory shown through phpsysinfo program (http://phpsysinfo.sourceforge.net/) and the one shown through telnet with "top" command. Phpsysinfo shown 10% of memory occupied yet the "top" command shown 1GB of ram occupied(close 100% usage). How come there is such huge difference.

I've never used phpsysinfo, but it seems to me it only counts used physical memory as the "active memory" part under top. It doesn't include all the other technically non-free memory as used.