Recently I purchased a second-hand 21.5" mid-2014 iMac for my parents and I'm hoping to replace its existing hard drive with an SSD. From what I understand the 2014 iMacs used Apple's blade SSDs but a) replacing a blade SSD is more complicated than replacing a hard drive, and b) unless the iMac was originally built to include an SSD (the one I have purchased was not) the required logic board connections are not present. So it seems my only option would be to replace the existing 2.5" SATA hard drive with a 2.5" SATA SSD. I've read the ifixit hard drive replacement guide and it seems straightforward enough, but I'm uncertain as to whether it's safe/advisable to replace the existing 2.5" HDD with a 2.5" SSD - some people have said it should be fine while others have said its not recommended (something to do with a thermal sensor). Is there anybody here who has completed this type of upgrade before who can confirm whether it's possible and maybe give some general advice? I'm experienced with hardware upgrades/repairs for PCs but this would be my first time performing such work on an iMac. Thanks!