Computers normally use RAM (random access memory) to run applications and programs. If RAM is low and there is not enough working memory to run all the programs on the system, a computer will display certain signs. Normally, low working memory results in slower applications, slow response time or results in the computer freezing. Each program on a computer requires a certain amount of RAM to run correctly. If you are using multiple programs or applications at once, there may not be enough RAM to run all the applications.
An easy way to tell your computer is running low on memory are notifications or error messages. If you try to launch an application but an error message appears stating something like "there is not enough memory to run this program," then you're running low on working memory. In Windows, a notification balloon may appear at the lower-right task bar stating that virtual memory is running low and requesting a clean of the hard drive.
Slow Response Time
When clicking on an application, opening a new window, switching between windows or clicking on icons, you will see a computer with low working memory show a reduced response time. For example, a computer with optimal working memory will immediately load and application in a few seconds, while a computer with low working memory will display the "Timer" icon on the cursor for a longer period or time, or the application will freeze as it is loading or may not load at all. Some applications may not close or other features (such as the "Start" menu) may take longer to respond when clicked.
If programs become unresponsive, then the working memory may be low. Multiple open applications and programs will become unresponsive and freeze if run at the same time, as low working memory cannot cope when running several programs at once. In some cases, programs may crash the entire system and cause the computer to freeze.
In some cases the graphics on the computer may become "pixelated." For example, the Desktop may appear discolored and icons may become abnormally large due to low work memory or other memory errors. Parts of programs or applications may seem to "disappear" or windows may not open when clicked. When an application or program freezes, it often display blank white spaces in certain parts of the application. If this occurs frequently, the working memory of the computer may be low.
Video and Sound Lag
Video and sound devices may begin to lag if memory is low. Like other applications, video or sound players will become unresponsive when there is not enough working memory available and the video or sound may lag, skip, freeze or become stuck in a constant loop. Other system sounds, which are not run by the computer as applications, may begin to lag. For example, you may receive an error message and the system sound for the error message may be delayed, may sound fragmented and broken or no sound will play at all.