The 2013 edition iMac has been on sale in September this year, some users complained that they encountered the computer not booting problem. Apple recently updated a technical assistance document, which said the new machine first boot may be time-consuming. Apple said that this is completely normal.
According to Apple’s statement, when the user press the power button for the first time, iMac will be seemingly unable to start for some time. The article goes on to explain that this is because the computer is optimizing for RAM power consumption configuration, which is completely normal. Depending on the memory size, the optimizing time varies, the longest is about half a minute.
“When the iMac optimization is complete, it will continue to start automatically,” the article wrote, “during this period never press the power button.” It is reported that the memory power optimization only boots at the first starting up, and then it will no longer run.
It should be noted that installing additional memory or clearing NVRAM will lead to previous setting reset, so it will experience a power optimization once again in boot.