Applications Running Slowly Under REAL/32

A common question posed to our support dept is "'I've upgraded my machine to a faster processor and now my application runs slower... Why"

The normal cause of this problem is a REAL/32 feature called idle detection. To solve this problem you will have to tune the idle detection to your new systems configuration.

Many interactive DOS programs are written without consideration for the effect of running on a multi-user system. These programs look repeatedly to see whether a key has been pressed, wasting processor time that could be used to improve the performance of other users and programs running on the system. When IDLE is set ON, the operating system detects the keyboard polling and clock checking that indicate an application is idle and allows other programs to use the saved processor time until the application needs to process such events as a mouse movement or keyboard entry.

The faster the processor, the more likely it is that the application will be thought to be idle, and so the idle parameters may well need to be changed:  

The syntax is IDLE = ON|OFF [,idlecount [,timeout]]

 (Please note: this command is only effective in Mconfig.sys, since it is a global setting; IDLE can then be turned on and off in batch files, menus etc, and on the command line, but the basic parameters can not be changed.)

 The idlecount and timeout parameters control the way in which idle detection is performed. REAL/32 monitors each application and counts the number of consecutive times a non-active function is performed (e.g. reading the keyboard) within a certain time period controlled by timeout. If the number counted exceeds idlecount, the application is marked as idle and is temporarily suspended to allow other programs to run. The default values of 4 for idlecount and 3000 for timeout are usually satisfactory - however if a program appears to be incorrectly idle detected it may be worth increasing idlecount to (say) 8 or sometimes much more in extreme cases.

If you still find that your system is running slow you may wish to check that you the OS is not using a large amount of the processor time. Click here to find out more

Copyright 1997-2002 Intelligent Micro Software. All rights reserved. Information in this document is subject to change without notice. Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or mark holders.
Last modified: Tuesday November 26, 2002.