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ProShare(TM) Software: Increasing Memory Resources
Contents:
INCREASING MEMORY RESOURCES FOR USE WITH PROSHARE SOFTWARE
The section in ProShare software's on-line help on "Improving
Performance" explains situations under which system memory resources may
be insufficient to complete certain operations. The ProShare software
requires that you have 12 megabytes of free virtual memory in order to
successfully use the advanced features in a typical environment.
If you plan to capture many pages from a presentation program using the
document import feature, you may require even more free virtual memory.
The program itself checks for 10 megabytes of free virtual memory when
it loads. If less than 10 megabytes is available, you'll see a message
warning about the effects of low memory. You can continue to run the
ProShare software application, but be aware that some operations like
print capture and document import may fail.
WHAT IS VIRTUAL MEMORY?
Virtual memory is a combination of RAM (physical system memory) and
reserved hard disk space. It is used by Windows to store program code
and data when applications are running. During the execution of a
program, parts of the program are in physical RAM and other parts are
swapped out to the hard disk. Because virtual memory is a combination
of RAM and hard disk space, it's possible to have more virtual memory in
your system than you have RAM installed. Because Windows uses virtual
memory to run programs, it's possible to run more applications
simultaneously than would be possible if Windows used only physical
memory to run programs.
HOW CAN I FIND OUT HOW MUCH VIRTUAL MEMORY MY SYSTEM HAS?
Windows can tell you the amount of virtual memory available at any given
time and the percentage of your total system resources that are
currently available for applications. To get this information, switch
to Program Manager, and choose Help/About Program Manager.... At the
bottom of the display box, your free memory (virtual memory) and % of
free resources are listed. The amount of free memory should be 12
megabytes or more, i.e., 12,000 KB. It is also recommended that your %
free be as high as possible.
WHAT CAUSES FREE MEMORY TO DECREASE?
Every time you run an application program under Windows, that program
uses some of your free virtual memory to run program code, and to store
and display data. Programs use additional memory as they:
* open new documents
* execute utility programs (like a spell-checker)
* perform other related program operations
For example, when you load ProShare software, it uses some of your free
memory. If you load a meeting file or capture some bitmaps to the
screen, more memory is used. If you use print capture to import a
document from another application, ProShare software launches the new
application, which in turn has its own memory requirements. Starting a
print operation in the second application uses memory, creating the
bitmap to display the captured data in the ProShare software notebook
uses memory. And so on.
As applications and operations are increased, more and more system
virtual memory is used. The ProShare software application has been
optimized to use bare minimum resources for program operations, but if
many other applications are running in the background, resources can be
drained below the minimum amount required for a particular operation.
OPTIMIZING MEMORY FOR USE WITH WINDOWS
The first thing to do when you're running low on virtual memory is to
optimize your use of existing memory so that the maximum possible amount
is available for Windows to access directly.
* Start by closing down some (or all) applications that are running
in the background or running minimized. In some cases, you'll need
to close and restart Windows to achieve the maximum available
virtual memory your system can have. (This is because some
applications don't de-allocate memory after they're closed.)
* Next, unload memory-resident programs and drivers that load into
conventional or extended memory. Or move some of these into upper
memory using a memory manager program like QEMM386, 386Max or
EMM386.
Note: Conventional memory is system memory with address ranges
0-640K, upper memory is 640K-1M, and Extended memory is above 1M.
* Since Windows can access extended memory directly, and since
extended memory is normally available in the largest quantities,
freeing up extended memory is usually the most efficient way to
gain virtual memory for Windows to use. To free up extended
memory, check your system for RAM disks or disk caches that are
created from extended memory. Eliminating these or reducing their
size will provide more virtual memory for Windows applications.
Freeing up conventional memory is a less effective way to optimize
memory, since you can often gain only a few Kbytes of additional memory.
However, it's always a good idea to provide the largest possible amount
of conventional memory when running Windows.
To free up conventional memory, start by unloading memory-resident
programs and unnecessary drivers. These are normally loaded in your
AUTOEXEC.BAT or CONFIG.SYS files. To remove them, remove or remark out
(by placing REM in front of them) the command lines in the AUTOEXEC.BAT
or CONFIG.SYS file. If you cannot unload drivers, use a memory manager
(mentioned above) to move some of your drivers and programs into upper
memory.
Memory manager programs normally come with a utility that automatically
checks your system and configures it to save the largest possible amount
of memory. Check the documentation that came with your memory manager
for instructions on loading drivers high and optimizing memory usage.
INCREASING THE AMOUNT OF VIRTUAL MEMORY IN THE SYSTEM
If optimizing memory usage still leaves you short of the 12 MB that
ProShare software may need, you'll have to increase the amount of
virtual memory in the system.
You can do this in two ways:
1) Increase the amount of system RAM available.
2) Create a permanent or temporary swap file.
To increase available system RAM, purchase additional memory chips and
install them in your computer. Contact your computer dealer for
information on installing additional memory chips.
To increase the amount of hard disk space allocated as virtual memory,
you need to create a Windows swap file, or increase the size of your
current Windows swap file.
HOW TO CREATE, DELETE, OR CHANGE THE SIZE OF A SWAP FILE
To create, delete, or change the size of a swap file, follow these
instructions.
Before creating a swap file, run a disk defragmentation utility. If you
already have a swap file, use these instructions to delete it before
defragmenting your hard disk, then create a new swap file after
defragmentation is completed. Do not run the defragmentation program
under Windows or if you are using a disk cache. See the user's manual
for your defragmentation utility for more information.
To create or delete a swap file:
Open the Windows Control Panel by double clicking the 'Control
Panel' icon
(usually located in Windows' 'Main' program group)
Double-Click on the 386 Enhanced icon in the Control Panel window
Click on Virtual Memory
Click on Change
In the 'New Settings' box, select Permanent or Temporary (See:
Permanent Swap Files) from the 'Type' box. Select 'None' to delete
an existing swap
file.
Enter a size in the 'New Size' box.
(Skip this step when deleting a swap file.)
Click on O.K..
Click on Yes to tell Windows you're sure about making changes to
virtual memory.
Click on O.K. to confirm the message that the swap file has been
created
Restart Windows when prompted.
Note: Windows cannot create a swap file from compressed or stacked hard
disk space.
PERFORMANCE CONSIDERATIONS FOR VIRTUAL MEMORY
The fastest type of virtual memory is physical RAM. The more of your
virtual memory that's provided by memory chips in your computer, the
faster Windows will run. Because of this, it's best to increase
physical memory whenever possible. For example, if you have a RAM disk
in extended memory, do not create a swap file on the RAM disk. Instead,
remove the RAM disk so that Windows can use the memory directly.
Creating a swap file on a network drive is not recommended. Network
swap files are extremely slow. If you must create a swap file on a
network drive, create a permanent swap file. Before creating the swap
file, you must make sure the network directory does not have a read-only
attribute, and you must have both create & write access to the
directory.
TEMPORARY VS. PERMANENT SWAP FILES
Windows allows you to set up 2 types of swap files, temporary or
permanent. Temporary swap files can be created out of fragmented hard
disk space, but permanent swap files can only be created out of
contiguous hard disk space. Depending on the amount of contiguous free
hard disk space available, performance concerns, and the amount of hard
disk space you need when not running Windows, one type of swap file may
be better for your configuration than the other.
Of the 2 types of swap files, temporary swap files are slower. The more
fragmented your hard disk is, the slower a temporary swap file becomes.
To maintain the best performance from a temporary swap file, run a
defragmentation utility on the hard disk frequently.
Temporary swap files are deleted when you close Windows, so a temporary
swap file doesn't take up any hard disk space when you're not running
Windows. If you need your free hard disk space for DOS applications
outside of Windows, then a temporary swap file is best.
A temporary swap file is a DOS file (WIN386.SWP) that is created on your
hard disk when Windows loads. It is deleted when you exit from Windows.
When configuring virtual memory for a temporary swap file, the default
recommended size is determined by 1) rounding the amount of available
physical RAM to the nearest 4M, then multiplying that amount by 4, and
2) checking that no more than 50% of the available free hard disk space
is used.
When configuring virtual memory from the Control Panel, you can create a
swap file smaller than the recommended size, but Windows will not allow
you to exceed the recommended size. If you wish to create a larger swap
file than the recommended size, you can edit the SYSTEM.INI file to
increase the free RAM multiplier. To do this, add the following line
to the [386enh] section of your SYSTEM.INI file:
PageOverCommit=x.
The default value for x is 4, which is the number used above. The
maximum value is 20. Increasing this value beyond 4 can cause Windows
performance to slow and should only be considered an option if adding
physical RAM is impossible. The swap file size can never exceed 50% of
the available hard disk space regardless of the amount of physical RAM
or the value set for PageOverCommit.
Once you've set up virtual memory for a temporary swap file, a swap file
of the requested size will be created every time Windows loads.
However, if the requested size swap file would use more than 50% of the
available hard disk space, the size is reduced to accommodate the 50%
limit. Windows does not warn you that it's creating a smaller swap
file, so if disk space is low, and if you add files to the hard disk, be
aware that your swap file size may be affected. If the swap file size
falls below 512K, performance will be seriously impaired.
Because temporary swap files can be created from non-contiguous hard
disk space, Windows may allow you to create a larger temporary swap file
than if you created a permanent swap file on the same system with the
same amount of free hard disk space.
Temporary swap files are deleted when you close Windows, so a temporary
swap file doesn't take up any hard disk space when you're not running
Windows. Permanent swap files are permanently allocated hidden files
created in a contiguous section of your hard disk. They are never
deleted so they continue to take up space even when Windows is not
running. The recommended size for a permanent swap file is calculated
using the same methods given above for a temporary swap file.
However, because permanent swap files must be created from contiguous
hard disk space, the recommended size that is shown in the Control
Panel's virtual memory setup may be smaller than the recommended maximum
size for a temporary swap file. If the recommended size allowed in the
Virtual Memory dialog box seems small, exit from Windows and run a
defragmentation utility program on your hard disk before creating a
permanent swap file. (Delete any existing permanent swap file and
unload any disk cache programs before defragmenting the drive.)
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