Upgrade OS X on Early 2008 Mac Pro desktop

[Maxwideman]

I have a Mac Pro desktop Early 2008 running OS X Yosemite. I have several questions:

1. I was just about to upgrade to El Capitain when macOS Sierra came out. However, the "Upgrade Button says that this version of 10.12.1 cannot be installed on this "Early 2008" Mac Pro computer. Is OS 10.12.1 really incompatible? Or is it because OS 10.12.1 has some features that the Early 2008 model does not support, such as on-board WiFi?

2. If the latter, how do I by-pass the "cannot be installed" notification?

3. Is macOS Sierra ready now for prime time anyway?

4. If I cannot do any of these things, how do I access (or find) the previous OS, that is OS X 10.11.x. El Capitain, and upgrade to that?

Your suggestions and recommendations will be appreciated. Thanks, R. Max Wideman

 

[Spawn_Dooley]

The following link is a good place to start, that is unless you have already read the info there. It states Mac Pro (Mid 2010 or newer) so your Early 2008 model isn't compatible, I'm afraid.

Upgrade to macOS Sierra

For El Capitan Apple states: Mac Pro (Early 2008 or newer), so if you want to upgrade to that OS then launch the App Store & search for it there. I can't guarantee that all the features of El Capitan will work for you. You can have a read about that here.

macOS Sierra by the way, is ready for prime time, it's just a matter for users to ensure their 3rd party apps will still operate.

Hope this helps.