Software diagnostic does allow for detection of possible problems when memory modules are already installed on the computer system.
These testers are built to support mass volumes of memory module testing.
These memory testers are usually docked onto an automatic handling system for high volume production testing, thus eliminating manual intervention by an operator.
Quality and features of this range of memory testers varies greatly depending on the manufacturer.
The key is to provide a simple to use tester at an affordable price that is still effective in capturing most memory faults and failures.
The detection and localization of non-permanent faults are extremely difficult with a memory tester.