I'm not a specialist, I just read up about it some time ago so take what I say with a grain of salt. Basically there's two issues affecting electronic chipsets

I'm not a specialist, I just read up about it some time ago so take what I say with a grain of salt. Basically there's two issues affecting electronic chipsets at high altitude : air density and cosmic rays. The reduction of the air density can mess with the cooling system. Cosmic rays contain radioactive particles which can cause soft failures to occur in solid state electronics. EDIT : Found an interesting paper about it with more details : https://pdfs.semanticscholar.org/6046/529f05a65e182ac9323ef8eb26b2075d0e13.pdf https://pdfs.semanticscholar.org/6046/529f05a65e182ac9323ef8...