A data compare technique for detecting memory errors on a computer's memory subsystem is disclosed. The technique simulates memory intensive software to determine if memory errors occur when the computer's memory subsystem is subjected to heavy memory usage. The technique copies an extensive test file, performs checksums of the original and copied test files and compares the checksum of the original file to the checksum of each copied file to identify checksum differences. The checksum differences indicate the occurrence of a memory error.