<sect1 id="memory">
<sect1info>

<authorgroup>

<author>
<firstname>Mike</firstname>
<surname>McBride</surname>
</author>
</authorgroup>

<date>21/10/2000</date>
<releaseinfo>1.00.00</releaseinfo>

<keywordset>
<keyword>KDE</keyword>
<keyword>KControl</keyword>
<keyword>memory</keyword>
<keyword>system information</keyword>
</keywordset>
</sect1info>

<title>Memory Information</title>

<para>This module displays the current memory usage.  It is updated constantly,
and can be very useful for pinpointing bottlenecks when certain applications are
executed.</para>

<sect2 id="memory-intro"><title>Memory Types</title>

<para>The first thing you must understand, is there are two types of "memory",
available to the operating system and the programs that run within it.</para>

<para>The first type, is called physical memory.  This is the memory located
within the memory chips, within your computer.  This is the <abbrev>RAM</abbrev>
(for Random Acess Memory) you bought when you purchased your computer.</para>

<para>The second type of memory, is called virtual or swap memory.  This block
of memory, is actually space on the hard drive.  The operating system reserves a
space on the hard drive for "swap space".  The operating system can use this
virtual memory (or swap space), if it runs out of physical memory.  The reason
this is called "swap" memory, is the operating system takes some data that it
doesn't think you will want for a while, and saves that to disk in this reserved
space.  The operating system then loads the new data you need right now.  It has
"swapped" the not needed data, for the data you need right now.  Virtual or swap
memory is not as fast as physical memory, so operating systems try to keep data
(especially often used data), in the physical memory.</para>

<para>The total memory, is the combined total of physical memory and virtual
memory.</para>

</sect2>

<sect2 id="memory-use">
<title>Memory Information Module</title>

<para>This window is divided into a top and bottom section</para>

<para>The top section shows you the total physical memory, total free physical
memory, shared memory, and buffered memory.</para>

<para>All four values are represented as the total number of bytes, and as the
number of megabytes (1 megabyte = slightly more than 1,000,000 bytes)</para>

<para>The bottom section shows you three graphs:  </para>

<itemizedlist>
<listitem><para>Total memory (this is the combination of physical and virtual
memory).</para></listitem>
<listitem><para>Physical Memory.</para></listitem>
<listitem><para>Virtual (or swap) memory.</para></listitem>
</itemizedlist>

<para>The green areas are free, and the red areas are used.</para>

<tip><para>The exact values of each type of memory are not critical, and they
change regularly.  When you evaluate this page, look at trends.</para>

<para>Does your computer have plenty of free space (green areas)?  If not, you
can increase the swap size or increase the physical memory.</para>

<para>Also, if your computer seems sluggish: Is your physical memory full, and
is the hard drive always seem to be running?  This suggests that you do not have
enough physical memory, and your computer is relying on the slower virtual
memory for commonly used data. Increasing your physical memory will improve the
responsivness of your computer.</para></tip>

</sect2>

<sect2 id="memory-author">
<title>Section Author</title>

<para> Michael McBride <email>mpmcbride7@yahoo.com</email></para>

</sect2>
</sect1>
