Screensaver Tip Reduces CPU Cycle Waste

Windows Tips & Secrets
1998 PLATINUM technology, Inc.

Reprinted with permission from Platinum Technology, Inc.

The value of screen savers has long been suspect. Most of us are aware that engineers designed monitors to prevent burn-in, even if left on all day to the same image. Microsoft responded to the NetWare server worm with a set of OpenGL screen-savers. While they are great at demonstrating Microsoft's support of the OpenGL standard, they are murder on a processor. Management loves them, however. They love to walk prospective clients or investors past the "Command Center", the glass-walled, controlled environment where dozens of monitors intently turn cubes into spheres. We've developed techniques to provide the network administrator with alternatives and some useful information in case of a server failure.

It's an image from Science Fiction. Row upon row of monitors busily displaying data, or crunching numbers or whatever they do, while no one is using them. Somehow, we don't feel we're getting the full use of our expensive servers unless we can look at them and see Well, something. So we give them the computing equivalent of busy work in the form of screen savers.

The next time you find yourself or your manager, drifting away to the 90's equivalent of the lava lamp, try this experiment:

• [Start]RunType Perfmon[Enter]

• [Ctrl+I]object: ProcessorCounter%ProcessorTimeAddDone.

• Right-click the desktop. Select PropertiesScreen SaverScreen saver. Select anything named 3D (OpenGL).

• Click Preview. Note the graph.

• Switch back to Performance Monitor. Note the graph.

When the screen saver is active, processor time pegs at 100 percent. Even the miniature version in the preview window takes up fully half of the processor time. For an application server, just running the screensaver can kill network performance. Run a few performance tests for yourself, with and without screen savers, just to see if you can improve speed.

The advantage to Windows NT screen savers is that you can force the workstation to lock, requiring a password. This is a nice safety net for administrators who neglect logging off the server. The best one to use is SCRNSAVE.SCR, which only blanks the screen.

Normally, when you logon to Windows NT, the screen saver is not active. You can make it active even at the logon screen by editing a value in the Registry. The value you need to change is found at HKEY_USERS \DEFAULT\ControlPanel\Desktop.

• Double-click ScreenSaveActive and set it to 1.

• Double-click SCRNSAVE.EXE and enter the full path to the screensaver (e.g., C:\WINNT\System32\SCRNSAVE.SCR).

• Double-click ScreenSave TimeOut and enter the number of seconds to wait before activation.

• Close the Registry Editor.

• Shut down and restart the GUI.

One tip we like use is to edit the Wallpaper displayed during logon to include useful information about your server. Lanma256.bmp or Lanmannt.bmp (depending on display colors) are the files used as he default wallpaper during logon. Find them in the \Winnt folder on your server. Open them up in any bitmap editor like MSPAINT and add text to the file. Put useful information like the server name, contact personnel and telephone numbers. Now, if no one can logon to the server, at least they have critical information to report problems. This can be very useful for servers attached to a Monitor switch box.

If you want, you can replace the entire logon wallpaper file with something else. Create a company logo to replace the Microsoft image. Design it to your company's specifications. Save the file in 8.3 format somewhere on the server's hard drive. You need to make a change in the Registry to point Windows NT to the new file.

• Open HKEY_USERS \DEFAULT\Control Panel\Desktop

• Double-click Wallpaper. Enter the full path to the new BMP file.

• Double-click TileWallpaper. Enter 1 to tile wallpaper. 0 not to tile.

• Double-click WallpaperStyle. Enter 0 for normal size. Enter 2 to stretch the BMP to fill the screen. (This won't work with tiled wallpaper).

• Close the Registry Editor.

• Shut down and restart the GUI.

If these Values are not in the Desktop Key, you can add them: Edit-New-String Value. Type in the names shown, preserving case.

Here's how you pitch it to management: Instead of a wall of monitors building pipes, spinning words, and endless mazes, have all the monitors proudly display your company logo. Now you have the server information you need, the performance boost, and you still have an attractive showcase. Until someone decides that your logo should be animated.

Additional Information

For more information, go to the Platinum Technology, Inc. web site at:
https://www.platinumtechnology.com.

We at Microsoft Corporation hope that the information in this work is valuable to you. Your use of the information contained in this work, however, is at your sole risk. All information in this work is provided "as -is", without any warranty, whether express or implied, of its accuracy, completeness, fitness for a particular purpose, title or non-infringement, and none of the third-party products or information mentioned in the work are authored, recommended, supported or guaranteed by Microsoft Corporation. Microsoft Corporation shall not be liable for any damages you may sustain by using this information, whether direct, indirect, special, incidental or consequential, even if it has been advised of the possibility of such damages.