Will trying out HSierra on an external usb ssd clone of my imac's hard drive result in a change to the firmware on the imac when I boot into it? Is there an option to keep the firmware the same? The reason I ask is this is a production machine so I don't want to find out that it no longer works properly with El Capitan when I reboot back into ElCap after trying out HSierra.
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Will HS change my imac's firmware?
- Thread starter stradify
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Yes, it will update your firmware if you install it directly.
It is possible to run HSierra without the new firmware as long as you use a drive that is not APFS. If you have or can be loaned access to another mac that can install it, You can install onto the USB drive and the other Mac will get it's firmware updated but once its installed, it wont try to update again and you can move the USB drive to try it on the production iMac.
It is possible to run HSierra without the new firmware as long as you use a drive that is not APFS. If you have or can be loaned access to another mac that can install it, You can install onto the USB drive and the other Mac will get it's firmware updated but once its installed, it wont try to update again and you can move the USB drive to try it on the production iMac.
The new firmware only add APFS booting ability to your Mac, it will NOT affect it's ability to boot any OS that work with your current firmware.
For someone like us still running Mac Pro 5,1. We can even boot 10.6.8 (Snow Leopard) with the new firmware.
For someone like us still running Mac Pro 5,1. We can even boot 10.6.8 (Snow Leopard) with the new firmware.
No, it's not just the SSD. I'm not sure that the SSDs firmware gets updated at all with the installation of High Sierra. The operating system installer will not do anything to firmware on an external, 3rd party SSD.
The firmware is stored on your Mac's logic board. NOT on the SSD (or any other storage).
Even internal SSD, the SSD's firmware is totally isolated and independent to the Mac's firmware. I am 99% sure this OS firmware update won't touch the SSD's firmware.