[CentOS] memory query

Dear All,

I have recently installed centOS 5 on DELL pentium 2.7ghz (model optiplex GX270) and have 512 memory

but the OS free command show me

Mem: 473876 469892 3984 0 11288 69384 -/+ buffers/cache: 389220 84656 Swap: 1020088 0 1020088

also cat /proc/meminfo show me same

MemTotal: 473876 kB MemFree: 4108 kB Buffers: 11040 kB Cached: 69376 kB SwapCached: 0 kB Active: 374072 kB Inactive: 67712 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 473876 kB LowFree: 4108 kB

also top gives me the same info

why i am loosing the memory.. appreciate your help

Thanks n reagrds

simon