Testing

For certain video card models, ATI gives permission to the AIBs (Add-in-Board-Manufacturers) to change the ATI reference design.
Common changes are changes in the output configuration like dual-DVI, changed memory, for example slower (= cheaper) or faster memory.
Since AIBs are always trying to cut costs, the most important change is reducing the number of PCB layers. The more layers a PCB has, the more expensive it is to make. So reducing the layer count of a video card from eight to six considerably drops cost, which allows more competitive prices.

Above changes considerably effect the general product quality as well as the stability. To make sure new designs show excellent performance, they are tested extensively.



Obviously it is not possible to test a new design for extended periods of time, so some tricks are used. The temperature and humidity is increased in a special test environment while the card is running 3DMark in a loop.



This test setup runs the card through five years of use. It does this by increasing the ambient temperature to 90°C while the card is powered on for about 14 days, which results in a speedup of 131x real time.



Not only high temperatures make life of a video card difficult, also low temperatures add strain to the compoents. This chamber cools the video card down to -5°C to +5°C. Now the video card is powered on and off over 200 times.
Mmm frozen video card, too bad that they wouldn't let me try overclocking in there.



The next environmental test simulates extreme changes in temperature and humidity. In that case from 55°C with 90% humidity to 0°C with 0% humidity. Test duration is 48 hours during which 3DMark is continually running with system reboots in between.



The last thermal test is the "Thermal Shock Test" which simulates repeated extreme temperature changes in a very short time.
Any material expands and contracts a little bit depending on temperature (the mercury thermometer is a real world application of that). Since the video card is made up from different materials, the expansion rate and amount is different, this puts mechanical stress on the solder joints and the components.



The contact tester is used to check if all connection on the PCB are right. A PCB is put into the device which measures resistance, impedance and can check for continuity and shorts.



This X-Ray inspection system allows to check that the individual layers of a PCB are properly aligned. It is also possible to check the quality of solder joints and search for bad BGA solder balls.

How possible defects look like:


BGA is the ball grid array attachment method used on ATI's GPU Cores. On the bottom of each GPU, there are hundreds of tiny solder balls (the R480 for example has 1345) which melt and form contact with the PCB. If the solder connection of only one of these balls is bad, the whole card will not work, so it is very important to rule out possible problems as early in the production process as possible.

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This concludes our tour through Sapphire's factory. I hope you enjoyed it and got a little bit of an idea how complex building a video card is.
Also I hope you noticed, that the factory is not 100% robot automated, many tasks are performed by humans. While low wages are certainly a reason for that, another important reason is that there are so many different video card products and the production lines produce different cards almost daily. Automated machines are best at constantly building the same product over and over, humans are much more flexible.

Finally, I would like to thank everybody at Sapphire who made this article possible.