MP 1,1-5,1 Firmware update and going backwards

[Andrew Montreal]

Hi all,

I am doing tests with my new video card. I created a new drive for all this to keep me original drive intact. It requires that I move to high sierra. I am presently at El Capitan. It also requires that I do firmware updates, both for High Sierra as well as Mojave. If I do these firmware updates will it prevent me from being able to return back to El Capitan with my original hard drive?

Thanks.

Andrew

 

[tsialex]

Hi all,

I am doing tests with my new video card. I created a new drive for all this to keep me original drive intact. It requires that I move to high sierra. I am presently at El Capitan. It also requires that I do firmware updates, both for High Sierra as well as Mojave. If I do these firmware updates will it prevent me from being able to return back to El Capitan with my original hard drive?

Thanks.

Andrew

Nope. You can boot past macOS releases back to 10.6.8 (it's really back to 10.6.4, but that is a special build that only the original mid-2010 Mac Pro restore disks have).

 

[Andrew Montreal]

Thank you. Then I shall venture forward into desert land.