Physical Memory??

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.

 

 

 

 

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