Linux in Government: Optimizing Desktop Performance, Part II
Today's Linux computer systems typically support 24-bit color, which translates to 16,777,216 colors. You might find that your system performs as well using 16-bit color, however, especially if you use virtual machines, such as VMware or rdesktop, to run Linux as a thin client on a Microsoft Terminal Server. You also can reduce the amount of memory dedicated to AGP Video chips and use that memory instead for system operations, especially if you need to squeeze resources such as RAM.
On Ubuntu, the default color settings are for 24-bit color. Changing that setting is a manual process. So, depending on your distribution, you can change the color depth from the command line:
su root or use sudo cd /etc/X11 or /etc/ edit XF86Config-4 or xorg.conf
depending on which X11 you have.
Scroll down to the section titled Screen and find the entry named DefaultDepth?. Change the setting you find there from 24 to 16.
In Fedora, you can change settings by selecting Launch->System Settings->Display and then changing the Color Depth to thousands of colors.
Last week we discussed the graphics cache for use with OpenOffice.org, as well as memory-per-object settings. This week we want to cover the issue of quick-starting OpenOffice.org's productivity suite. OpenOffice.org looks like a collection of separate programs such as a word processor and a spreadsheet program. We might consider it as being similar to Microsoft Office, where you can buy Word or Excel separately.
In actuality, OpenOffice.org consists of a single large application with different interfaces. Thus, it requires time to start the first OpenOffice.org application you use. When you launch OO Writer, for example, you might want to get a cup of coffee. But if you leave one of the applications open, you can open a new document quickly. The big OpenOffice.org application already exists in memory from when you started, in this case, OO Writer.
A couple of utilities exist that preload OpenOffice.org. One, called Quickstarter or oooqs, exists for KDE; another, called ooqstart-gnome, exists for GNOME. We have not seen new development on the later utility, though, and it often causes an error message.
You also can use a built-in program called ooffice -quickstart, which you can start manually from the command line. The command is
$ ooffice -quickstart &
To use it, start ooffice -quickstart manually or have it launched automatically when you start your window manager or desktop. You then can start up your word processor, for example, work and then close the applications. But as soon as you close OpenOffice.org, the background quickstart process automatically dies.
The scripts used by oooqs and ooqstart-gnome do not experience this problem. So, you may want to use a script modified from Linux Desktop Hacks, published by O'Reilly & Associates. With this method we create a script and place it in a file called /usr/local/bin/oostay. The script looks like this:
#!/bin/bash # Restart ooffice -quickstart every time it exits instances=`ps ax | grep -e -quickstart | grep -v grep | wc -l` if [ $instances == 0 ]; then while true; do ooffice -quickstart ; done else exit 1 fi
After creating it, make it executable with the following command:
# chmod +x /usr/local/bin/oostay
You can have it start when you logon to your desktop by specifying it in the Sessions dialog in GNOME, for example. See Figure 3.
Firefox running on Ubuntu seems to be slower than it is on Fedora Core 3 and some other Linux distributions. You can speed up its launch and rendering of Web pages, however, with a few changes. You have to open Firefox and in the address box type about:config. You then can use the about:config screen to tweak performance by increasing the maximum number of connections to different aspects of the network. Some setting to change and their values include:
network.http.max-connections 128 network.http.max-connections-per-server 48 network.http.max-persistent-connections-per-proxy 24 network.http.max-persistent-connections-per-server 12
When you find a text string such as network.http.max-connections in the about:config screen, double-click the entry and a text box pops up allowing you to change the values. If you simply want to change a default from true to false, you can double-click the appropriate text string and the value changes. Each text string provides a status to the right of the property field. It displays either a default or user set status. So, you always can go back to the default settings.
For broadband users, Firefox responds to some changes in its default values for the following properties:
network.http.pipelining network.http.proxy.pipelining network.http.pipelining.maxrequests
The default browser provides one request to a Web page at a time. Enabling pipelining makes several, which can speed up page loading. Alter the entries as follows:
Set network.http.pipelining to true.
Set network.http.proxy.pipelining to true.
Set network.http.pipelining.maxrequests to 30. This means it makes 30 requests at once.
Right-click anywhere on the about:config page and select New->Integer. Name it nglayout.initialpaint.delay and set its value to 0. The browser waits before it acts on information it receives; this changes the behavior so it acts immediately.
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