Testing platforms designed with Intel® Architectures (IA) can be extremely difficult and testing memories near impossible. If you are still using a production BIOS to configure your memory subsystem during manufacturing test, you may be missing issues that are an artifact of how the BIOS configures the memories.
Historically, it has been acceptable to run a post boot memory test in production. However, newer BIOS implementations can hinder that approach. Understanding the complexities of the BIOS and in particular Memory Reference Code (MRC) will help the test designer see the challenges in using a traditional approach.