Upgrading Your iMac Late 2009: Towards macOS Catalina and Beyond

The iMac late 2009 models, released in September 2009, have been stalwarts in many computer enthusiasts' households for over a decade. However, as technology advances, running modern operating systems becomes increasingly challenging. Many users wonder if it's feasible to upgrade their iMac late 2009 from macOS Sierra (10.13.6) to the more recent macOS Catalina (10.15).

Is It Possible to Upgrade?

Unfortunately, the answer is generally not advisable. While some old Macs can be hacked to run newer operating systems, this often comes with significant downsides:

The performance will be severely limited. The system will be highly unstable and prone to crashes. There will be a high risk of system failure on a regular basis.

Given these issues, it is much more practical to run Linux on your iMac. Many Linux distributions are optimized for older hardware and can provide a stable, functional environment.

Does Your iMac Late 2009 Support High Sierra?

According to some sources, it is technically possible to upgrade your late 2009 iMac to macOS High Sierra (10.13.6). However, official documentation does not explicitly confirm this. Even if such an upgrade is possible, it is important to consider the age and hardware limitations of your device. Running a modern operating system on such old hardware may result in poor performance.

Apple supports new operating systems in older hardware for a period ranging from five to seven years. Therefore, the most recent version of macOS your iMac can realistically run is macOS High Sierra (10.13.6) if it is an "Early 2009" iMac, or macOS Sierra (10.13) if it is a "Late 2009" iMac.

Hack Attempts and Unofficial Patches

There have been attempts to run newer operating systems on older iMacs using unofficial patches. For instance, the dosdude1 Catalina Patcher allows users to run Catalina (10.15) on older Macs, but with significant limitations:

The performance of the iMac will be significantly compromised. The system will not support hardware acceleration for older GPUs, specifically the AMD Radeon HD 5xxx and 6xxx series. Applications that require hardware acceleration may not function properly.

In addition, Catalina uses APFS (Apple File System), which does not work with traditional hard disk drives (HDDs). One workaround is to use an external SSD, but this solution may not be viable given the iMac's limited USB 2.0 ports, which can significantly impact read and write speeds.

Better Alternatives: Linux and Newer Hardware

While upgrading your iMac late 2009 might be technically possible, it is often more practical to consider alternative solutions:

Running Linux: Many Linux distributions are designed specifically for older hardware and can provide a stable, functional desktop environment. Refurbished iMacs: A refurbished 2013 iMac can be purchased for around $150 from organizations like OWC (Other World Computing), offering significantly better performance and a more satisfying user experience.

In conclusion, while there are ways to run newer operating systems on your iMac late 2009, it is generally not recommended due to the associated risks and performance issues. Consider transitioning to modern hardware or using Linux to ensure a stable and efficient computing environment.