New 21.5-inch iMac has upgradable CPU, RAM, and 2.5-inch drive
Apple has long been under fire from PC enthusiasts for using proprietary hardware, but the soldered SSDs introduced in the 2016 MacBooks were an especially unwelcome escalation. With the MacBook series completely locked down, you might expect that Apple's desktop systems would follow suit — yet you'd be surprised to learn that iFixit's teardown of the new 21.5-inch iMac has revealed the CPU, RAM, and 2.5-inch drive are all upgradable.
Apple's 2015 21.5-inch iMac scored a 1-out-of-10 on iFixit's repairability scale: the RAM, HDD, and CPU were all soldered to the logic board. The 2017 model, however, has been revealed to have socketed RAM, a replaceable 2.5-inch drive, and a socketed CPU. The downside is that it's still very difficult to get inside the fused-glass display and access the motherboard inside — not to mention the fact that Apple has put warranty voiding stickers on the screws to the heatsink. Still, if you need to upgrade your CPU in your iMac, it's a good bet that your warranty will be just about up anyway.