MacStories> OWC Blog
That is to say: we can buy an iMac, but if we change the hard disk for a bigger or more powerful one of another brand the computer will work incorrectly : the Apple Hardware Test fails and the fans are set at maximum, generating a very annoying noise. And it is not that Apple manufactures its own hard drives, but the “official” ones of the brand have a exclusive firmware that makes them unique and a customized SATA connection cable that moves away from the standard 4-pin to have 7 pins. Thus, even if we put the same model of hard disk but without being the one provided by Apple the computer works incorrectly.
This brings us back to the eternal debate: Is it worth customizing an iMac? Yes, you can get more power. But with this kind of action, Apple makes it pretty clear that it doesn’t want us to even bother opening the computer case. While OWC talks about a bad attitude on Apple’s part, you can also say that Apple simply wants to ensure that the computer will work properly and will not be responsible for customizations that hand-held users may make.
The best thing is to buy an iMac without expectations of customizing it (especially if we do not dare to open it to take a look at its entrails), and having clear that you can still update the RAM memory retaining the warranty without problems and connect devices with an enviable performance through the Thunderbolt port. By the way, we can see all the components of the new iMac in iFixit, which as usual has dismantled the computer part by part.