After the experts at iFixt dismantled the 21.5-inch Retina 4K iMac, they discovered that both the processor and the memory were not plugged into the motherboard, making it possible to switch them, but that was not so easy.
The 21.5 iMac had random memory and a processor that was sold to the motherboard in previous years, so it was hard for non-professionals to change it.
The processor can not be reached as easily as some might expect; it is placed on the back of the base plate behind a lot of other components, and placed underneath the glued part underneath the glass. But for the first time in years now the CPU can be replaced or updated without problems.
This will allow those who want to buy and update this low-cost device to become much stronger, which can save hundreds of dollars compared to buying models that have more powerful processors or a larger memory chip, but this may invalidate the device’s warranty.
Apple has announced that the next iMAC Pro will not have an interchangeable processor and memory, but the 27-inch iMAC has a removable memory processor and memory for some time.
The new 21.5-inch iMAC is much more updatable than the 2015 model, which scored as low as iFixit 1/10; and although the new model is not easy to fix or update, the idea is executable, 3/10 degree.