In about 5 years they start losing charge, and there is no return from there. Magnetic storage last longer usually, tapes ~20 years, but they require certain c

In about 5 years they start losing charge, and there is no return from there. Magnetic storage last longer usually, tapes ~20 years, but they require certain conditions and it does matter if you store them vertically or horizontally. Hard drive can last very long, but they have moving parts, which is a completely different world of potential problems if they are power off for a long time. I dug into archiving my stuff a few months ago, ended up using single layer panasonic blu-ray. They used to be advertised as 50 years archival grade, but panasonic split it into on that's without the archival label and one with - the latter is nearly impossible to get in Europe and is very expensive. We'll see in 10-15 years. Mdisc, mentioned earlier, could do 1000 years in clinically-proven accelerated aging tests and withstood hard weather fairly well: http://www.mdisc.com/ http://www.mdisc.com/ http://www.zdnet.com/article/torture-testing-the-1000-year-dvd/ http://www.zdnet.com/article/torture-testing-the-1000-year-d... There are numerous studies and accelerated aging test on CDs and DVDs, but I couldn't find anything similar to Blu-Rays yet, though I would be interested: http://www.thexlab.com/faqs/opticalmedialongevity.html http://www.thexlab.com/faqs/opticalmedialongevity.html It might be worth mentioning that 'Archival Disk' is a thing now, with 300GB-1TB capacity from joint efforts of Sony and Panasonic, but it's completely out of the consumer pricing for now: https://en.wikipedia.org/wiki/Archival_Disc https://en.wikipedia.org/wiki/Archival_Disc