Owners of the new iMac range that launched earlier this month face a difficult task if they wish to upgrade their hard drives, it has emerged.

According to Other World Computing, Apple has changed the SATA power connector in the new iMacs from a standard 4-pin power configuration to a custom 7-pin configuration.

In addition, temperature control is regulated by proprietary Apple firmware, meaning that if the original drive is replaced the hard drive fans spin constantly at maximum speed. What's more, using a new drive will make the iMac fail the Apple Hardware Test.

The new iMacs come with a range of hard drive options, with a choice of 500GB, 1TB and 2TB hard drives as well as a 256GB solid-state drive to choose from.

However, those who don't want to pay the additional £400 Apple charges for an SSD, or the extra £120 to upgrade from a 1TB to 2TB hard drive will find themselves in a tricky situation, as will anyone whose hard drive fails once the warranty expires.