I am running Fedora Core 4 on my web server... I have over 250mb total memory. However, I am experiencing some slow processing at the terminal when people are accessing my box via httpd. I noticed that I only have a fraction of my total memory available. Sometimes it drops between 4 and 12 mb free... Can anyone explain or suggest a fix for this?

---Memory Information---
MemTotal: 255636 kB
MemFree: 11688 kB
Buffers: 30520 kB
Cached: 48228 kB
SwapCached: 0 kB
Active: 163552 kB
Inactive: 27032 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 255636 kB
LowFree: 11688 kB
SwapTotal: 327672 kB
SwapFree: 326824 kB
Dirty: 248 kB
Writeback: 0 kB
Mapped: 147848 kB
Slab: 45996 kB
CommitLimit: 455488 kB
Committed_AS: 348056 kB
PageTables: 3372 kB
VmallocTotal: 770040 kB
VmallocUsed: 2380 kB
VmallocChunk: 767352 kB
HugePages_Total: 0
HugePages_Free: 0
Hugepagesize: 4096 kB

The linux kernel always uses the complete memory.
As you see 78MB are used for buffers and cache to prevent a (much slower) harddisk access.

Thanks for your response. When killing a few processes that were hogging memory, as revealed by ps -aux, and limiting the number of httpd processes, I was able to increase my free ram to ~65mb.