I recently installed Linux Mint on my old 2009 Intel iMac that I hadn't used in years. While Mint runs, it's a bit slow, and I'm looking to switch to a lighter distribution. However, I'm having trouble booting from USB to install another OS. I've tried various startup key combinations to interrupt the boot sequence, but it goes straight to the Mint login screen. Does anyone know how to prioritize USB booting on this model?
3 Answers
You might want to check out an extension called 'boot to UEFI'. Alternatively, try powering off your iMac and then booting it up while holding down the power button. This might help you access the boot options.
Just a heads up, holding the power button for options is mainly for Apple Silicon. It doesn't apply to Intel Macs like yours.
Honestly, your iMac might be just fine with Mint. It’s not the fastest, but considering its age, it might be better to stick with Mint rather than stressing over a new install.
If Cinnamon is running slowly for you, consider switching to Mint's XFCE version instead. It’s lighter on resources and could give you a better performance.

I tried holding the power button, but it didn’t work for me. I’ll definitely look into the boot to UEFI thing though!