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Elevation Plays a Role In Memory Error Rates

Posted by Soulskill on from the another-reason-not-to-calculate-prime-numbers-on-mt.-everest dept.

alphadogg writes "With memory, as with real estate, location matters. A group of researchers from AMD and the Department of Energy's Los Alamos National Laboratory have found that the altitude at which SRAM resides can influence how many random errors the memory produces. In a field study of two high-performance computers, the researchers found that L2 and L3 caches had more transient errors on the supercomputer located at a higher altitude, compared with the one closer to sea level. They attributed the disparity largely to lower air pressure and higher cosmic ray-induced neutron strikes. Strangely, higher elevation even led to more errors within a rack of servers, the researchers found. Their tests showed that memory modules on the top of a server rack had 20 percent more transient errors than those closer to the bottom of the rack. However, it's not clear what causes this smaller-scale effect."

3 of 190 comments (clear)

  1. This isn't news by dszd0g · · Score: 4, Informative

    This isn't news. Companies that make supercomputers have known this for decades. The one I worked for 15 years ago used a high elevation test environment in Colorado to verify error correcting capabilities. Even the article says that the results were not a surprise.

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    1. Re:This isn't news by edibobb · · Score: 4, Informative

      From the article: "It is well known that the altitude at which a data center resides has consequences with regards to machine fault rates. The two primary causes of increased fault rates at higher altitude are reduced cooling due to lower air pressure and increased cosmic ray-induced neutron strikes."

  2. Muons by Roger+W+Moore · · Score: 4, Informative

    Then wouldn't you expect a cascading rate of failures from 20% down to the baseline bottom rack in a linear fashion?

    The majority of cosmic rays that make it this far are muons. These are relatively penetrating and I highly doubt that a few centimetres of metal and plastic will have anything like a 20% effect. 60m underground with the ATLAS detector at the LHC we still get a reasonable rate of cosmic rays and we use them for calibration when there is no beam. While the rate is reduced 60m of rock is far, far more shielding than a few computers plus many cosmics passing through you come at an angle so the stack above will have no effect on shielding these.

    I expect that heat and vibration will be the most likely causes.