According to EveryMac (see bottom of link, by footnotes)
http://www.everymac.com/systems/apple/imac/imac-aluminum-faq/imac-intel-aluminum-how-to-upgrade-memory.html
the 2011 EDUCATION model is EFI capped at 8gb ram. I remember reading about it when it came out. It is Apple's way of 'differentiating' between the education model and the regular model. Besides, everyone knows that no educator would want more than 8gb of ram...
http://www.everymac.com/systems/apple/imac/imac-aluminum-faq/imac-intel-aluminum-how-to-upgrade-memory.html
the 2011 EDUCATION model is EFI capped at 8gb ram. I remember reading about it when it came out. It is Apple's way of 'differentiating' between the education model and the regular model. Besides, everyone knows that no educator would want more than 8gb of ram...