Who really made my memory chips?

Tracing quality to the source.
Very few companies in the world actually make memory chips, but literally hundreds of companies sell memory modules.

Take a look at the markings on any chip in your computer. Each chip is covered with numbers. Believe it or not, all those little numbers mean something. They are used for traceability.

If you have a problem with a module and want to return it, one of the first things you will be asked is to read this information. By decoding these numbers, any of the more reputable chip manufacturers (not just DRAM manufacturers) can determine when the part was built, in which Fab, and they can often trace it back to the actual wafer the part came from. By building databases with this information, chip manufacturers are better able to pinpoint the cause of a problem, correct it, and make the next lot that much better.

In addition to the state-of-the-art wafer processing equipment used in DRAM manufacturing, part of what you pay for when purchasing top-tier memory is testing.

The most quality-conscious chip manufacturers, like Micron, will put every single chip through an extensive series of tests rather than just checking a sample of parts. They will test chips under normal operating conditions as well as under varying voltages, temperatures, and other "stressful" conditions.

Chips also go through a burn-in process at elevated temperatures to help identify any borderline parts. This process accelerates failure normally seen as "infant mortality." Chips that would fail early during actual usage will fail during burn-in. Chips that pass have a life expectancy much greater than that required for normal usage. Burn-in further helps to prevent failures from reaching you, the end user.

What's the difference between top tier and generic memory? »