Your operating system
(Windows 7) takes care of managing the CPU and memory for you. Even so,
you can do some things to improve performance as it relates to your
system's memory and CPU. The following sections offer some tips.
1. Conserving memory
One of the best things you
can do to improve your computer's performance is ensure that it has
plenty of memory. Initially, that means making sure the computer has a
sufficient amount of physical memory installed. You should consider 1 GB
a minimum, although Windows can run with less. If you use lots or
programs at once, or use applications that require a lot of memory,
consider having at least 2 GB of RAM in the computer, if not 4 GB.
Having a lot of memory is
part of the solution, but managing the memory you do have is equally
important. You can optimize your computer's RAM in these ways:
Reduce the number of programs you run concurrently: If you aren't using a program, close it to reclaim the memory it is using. You can always open it again later if you need it.
Minimize the number of programs you install on your computer:
Do you really need a program on the tray that tells you what the
weather is like outside? Do you really need a gadget on the desktop that
shows a tiny slide show? All of the little add-on programs you install
and run on your computer, even if they are running in the background,
consume resources. The fewer, the better.
Reducing the number of
programs running at one time not only improves performance from a memory
perspective, but it also reduces the load on the CPU, making processing
cycles available to those programs that do need to be running.
2. Managing virtual memory
In the very early days of DOS, a
computer could run only one program at a time. Programs had to be
written to fit in the available (and minimal) memory in the computer. In
today's Windows OS, you can run almost as many programs as you want at
one time. The capability to run multiple programs is due to the design
of today's CPUs and of the OS itself. The capability to manage memory
effectively for all of those programs is due in part to the use of virtual memory.
Modern computers can use two types of memory. The first type is physical memory
(RAM), which consists of physical memory chips on memory modules (small
circuit boards) that plug into the computer's motherboard.
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The amount of RAM shown on the General tab of the System Properties dialog box is the amount of physical RAM in your system.
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The second type of memory is virtual memory,
and Windows 7 uses the computer's hard drive for that, using a file on
the drive as a place to store data as an alternative to physical memory.
The area on the hard drive that's used as virtual memory is called a paging file,
because data is swapped back and forth between physical and virtual
memory in small chunks called pages. When you fill up both your physical
memory and virtual memory, the computer doesn't just stop and display
an error. Rather, it displays a message in advance, warning that the
computer is running low on virtual memory and suggesting that you make
room for more.
Because the virtual memory is
just a paging file on the hard drive, you can easily add more just by
increasing the size of the paging file. You don't have to buy or install
anything. This is unlike physical memory, in that the only way to
increase physical memory is to buy and install more RAM.
To manage virtual memory in
Windows 7, open the System applet from the Control Panel and click the
Change Settings link. In the resulting System Properties dialog box,
click the Advanced tab and click the Settings button in the Performance
group. Then, click the Advanced tab in the resulting Performance Options
dialog box (Figure 1).
The Virtual Memory area on this dialog box shows the total paging file
size for all drives. To adjust the settings, click the Change button to
open the Virtual Memory dialog box shown in Figure 2.
In most cases, it makes
sense to select the top check box Automatically Manage Paging File Size
for All Drives to allow Windows to adjust the page file.
If you don't want Windows to
manage the page file for you, your main options in the Paging File Size
for Each Drive area of the Virtual Memory dialog box are as follows:
Custom Size: You choose where you want to put your paging file(s), their initial size, and maximum size.
System Managed Size: Tells Windows to create and size the paging file automatically for you.
No Paging File: Eliminates the paging file from a drive. Not recommended unless you're moving the paging file from one drive to another.
If you have multiple hard
drives, you can get the best performance by using the least busy drive
for virtual memory. For example, if you have a D: drive on which you
store documents, it may be better to use that, rather than the C: drive,
because the C: drive is pretty busy with Windows and your installed
programs.
If you have multiple physical drives,
you can get a little performance boost by splitting the paging file
across the two drives. A single drive that's partitioned into two or
more partitions, to look like multiple drives, doesn't count. You don't
want to divide the paging file across multiple partitions on a single
drive, because that will have the reverse effect of slowing things down.
If you do opt for a custom
size, you can work with any one hard drive at a time. The drives are
listed by letter and label at the top of the dialog box. In the example
shown, all of the partitions actually reside on a single drive.
If you don't select the check
box at the top of the Virtual Memory dialog box, you'll need to set the
paging file sizes individually. For example, to move the paging from
drive C: to D:, first click Drive C: at the top of the dialog box,
choose No Paging File, and then click the Set button. Then, click Drive
D:, choose Custom Size, set your sizes, and click Set.
The Total Paging File Size for
All Drives section at the bottom of the dialog box shows the minimum
allowable size, a recommended size, and the currently allocated size
(the last measurement being the sum of all the Initial Size settings).
The recommended size is usually about 1.5 times the amount of physical
memory. The idea is to prevent you from loading up way more stuff than you have physical RAM to handle, which would definitely make your computer run more slowly.
If your computer keeps showing
messages about running out of virtual memory, you'll definitely want to
increase the initial and maximum size of the paging file. A gigabyte
(1,024 MB) is a nice round number. But if the computer runs slowly after
you increase the amount of virtual memory, the best solution would be
to add more physical RAM.
If you do change the
Virtual Memory settings and click OK, you'll be asked if you want to
restart your computer. If you have programs or documents open, you can
choose No and close everything first. But because the paging file is
only created when you first start your computer, you'll eventually need
to restart the computer to take advantage of your new settings.
3. Priorities, foreground, and background
Your computer's CPU and RAM are
very busy places, with potentially thousands of tasks occurring at one
time. To try to optimize performance, Windows prioritizes those tasks.
Your application programs typically run in the foreground,
which means that when you click an item with your mouse or do something
at the keyboard, fulfilling that request gets top priority in terms of
being sent to the CPU for execution.
Most processes, by comparison, run in the background.
This means that they get a lower priority and have to momentarily step
aside when you tell Windows or an application to do something. For
example, printing a document is treated as a low-priority background
process, and for a good reason. All printers are basically slow,
mechanical devices anyway. So, by making printing a low-priority
process, you can continue to use your computer at near normal speeds
while the printer is slowly churning out its printed pages.
4. Controlling CPU priorities
By default, programs that
you're using are given a higher priority than background processes. It's
possible to reverse that by giving processes a higher priority than
applications. If you have an intensive background task running and want
to give it higher priority, you can reverse the order. Or, if you want
to make sure that your applications are getting top priority, as they
should be, follow these steps:
Right-click your Computer icon from the Start menu, and choose Properties to open the System window for your system.
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The System icon in Control
Panel also opens the System window. If Control Panel opens in Category
view, click System and Security and click the System link.
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Click
the Advanced System Settings link on the left side of the screen to
bring up the System Properties dialog box. Click the Advanced tab in the
System Properties dialog box.
Under the Performance heading, click the Settings button. The Performance Options dialog box opens.
In the Performance Options dialog box, click the Advanced tab shown previously in Figure 49-4.
The Processor Scheduling
options determine whether your actions, or processes, get top priority
when vying for CPU resources to do their jobs. If you choose Background
Services, your computer may not be as responsive as you'd like, but
background tasks will get higher priority. So for example, if you are
running a scan of your system in the background and want it to finish
faster, select Background Services in the Performance Options dialog box
and click OK.
NOTE
Choosing
Background Services won't make your printer print any faster. There's
really nothing you can do to speed printing, other than use the
printer's Draft mode (if it has one). But even so, printers are just
inherently slow mechanical devices.
