Revision Control: Ensure Every Computer You Buy is Consistent
by Michael Bowling, on Jan 3, 2018 10:19:12 AM
When I was in high school, I took some classes with a set of twins named Timmy and Tommy. Initially I would say they were identical in every way and I’ll confess that I may have mixed up their names a few times. Still, it didn’t take long before I could easily tell the difference between the twins at a glance…both small physical differences, but more importantly I could tell a large personality difference. As strange as this may sound, the computer assembly process is similar.
At first glance you may think that two 2U rackmount chassis are identical, but once you take a closer look you’ll realize that the cables are routed differently, the hard drive is installed in a different bay, the memory is populated in different channels, the GPU card is plugged into a different PCIe slot, etc. To the casual observer these differences may seem minor and insignificant…but to high-availability, critical applications such as the military or cybersecurity these “small” inconsistencies add up and have large quality implications. Computer hardware revision control & consistency is also important for healthcare and industrial applications where certifications (CE, UL, CCC, FCC, etc) cost a lot of time and money to get approved and then must stay exactly the same for as long as possible.
So what are the best ways to ensure every computer I buy is consistent?
- Proper documentation and processes
Make sure that your supplier has thorough assembly documentation and assembly processes. This ensures a consistent build quality. Check their ISO 9001 certificate which will make sure they have been reviewed by an independent quality professional at least once a year. They should have automatic processes in place to notify you of any form, fit, or functional changes to their computers.
- Manufacturer vs Supplier
There are many different types of computer suppliers. It is critical to understand if your supplier is the actual designer and manufacturer of the processor board OR are they simply installing another company’s products into a chassis for you. The most critical components in your computer system are not the fans and hard drives…the components in your computer that will have the most impact on your application are soldered down onto the processor board (e.g. ethernet controllers, PCIe switches, CPU chipsets, BIOS, etc). If the company you are buying your computer from is not the OEM (original equipment manufacturer) then you are unlikely to get notified of changes on the boards.
- Only Spec What You Need
It is tempting to allow yourself flexibility for future options that may or may not happen (e.g. extra drive carriers, extra power cables, etc), but this increases cost and risk. Eliminate any unnecessary cables, drives, etc. The more variability the more potential for inconsistencies in the final assembly.
Most people just buy a computer and move on in life with no expectation that they will need to buy the EXACT same computer for many years. For critical applications, it is vital to ensure consistency, especially for applications that have an extended product lifecycle. You only want to go through the specification, testing, and certification process once…not over and over again because your computer supplier can’t ensure the exact same form, fit, and function.
Read my whitepaper on hardware revision control where I demonstrate how two computers (one with and the other without revision control in place) compare to each other over time.