Q: MacBook (Mid 2009) - OS SIERRA

Is it a MacBook or a MacBook Pro? There is a difference.

http://www.apple.com/osx/how-to-upgrade/

If your Mac is not Compatible with Sierra but you Have Not Upgraded to El Capitan  - https://discussions.apple.com/docs/DOC-10692

The mid 2009 MacBook Pro is not compatible with Sierra

This

http://www.apple.com/macos/how-to-upgrade/

includes

Mac Hardware Requirements

For details about your Mac model, click the Apple icon at the top left of your screen, choose About This Mac, then choose More Info. These Mac models are compatible with macOS Sierra:

• MacBook Pro (Mid 2010 or newer)
• MacBook (Late 2009 or newer)

wingbone wrote:

 

I have a MacBook Pro,

And that's where it makes a difference.  Read the links I provided as to exact hardware requirements and which models cannot be upgraded.

The question is WHY?  Mid 2009 not supported, Late 2009 is supported.  Basically the same machine.  Is it just a ploy to get you to drop some bucks on Apple for a new computer or is there a technical reason?  No explanation given.  I'd like to see Apple address the issue.

One difference is the the late 2009 uses and Intel Direct Media Interface

https://en.wikipedia.org/wiki/Direct_Media_Interface

While earlier ones use a Front Side Bus for internal communications

https://en.wikipedia.org/wiki/Front-side_bus

But see:

http://forums.macrumors.com/threads/macos-10-12-sierra-unsupported-macs-thread.1 977128/

Why does apple put it on computers that should not receive it?

They don't, that's why you can't download it.

I think it isn't true because the Macbook late 2009 haven't the DMI and it is suitable to update with sierra! Why?

the Macbook pro mid 2009 is more performant then Macbook late 2009 but it isn't suitable for the update!

See the difference between the models at http://apple-history.com/compare/mbp_15_mid_09/mb_late_09, they are the same.

Only Apple would know, we're not Apple, just other Apple product users like yourself.

Yes, only Apple knows, but Apple has not responded to lots of unhappy owners with a Technical Explanation as to why a MacBook 2009 is supported while a MacBook Pro 2009 is not.  I know that many manufacturers only support equipment for 7 years.  Understandable for hardware due to physical inventory and other issues.   What I fail to understand is why they don't just allow users to install at own risk.  Yes, I know that there hare hacks and work-arounds to get it to install, but I don't want to do that.  Just let me install the software at my own risk and let me decide if the performance isn't satisfactory.  I can always go back and put El Capitan back if I don't like it.  Give me a good TECHNICAL reason not to support a MacBook Pro, mid 2009.  That's all I ask.  I just want to understand why I'm being punished for being happy with my perfectly good Mac that I've been using happily for the past 7 years.

Once again, you're not talking to Apple here.

If you want to talk to Apple, use this: http://www.apple.com/feedback/

Yes, i know. I have just said that motivation isn't the DMI!

For the macbook pro mid 2009 I think it's just a marketing operation. Very disappointing from Apple

...Apple has not responded to lots of unhappy owners with a Technical Explanation

...why they don't just allow users to install at own risk. 

Computers have become ubiquitous in society but most people are baffled by an on/off switch, much less a technical explanation.  Many users find the concept of purchasing a new computer every 5 years perfectly normal.  If Apple let people just install Sierra on any machine they desired you could find huge numbers of posts here from people asking how to solve a problem with Sierra running on a 2006 MacBook with 1 GB RAM and a 5400 rpm HDD.  No, they would NOT read the warning about possible issues. People don't read these days.  It's just safer to draw the line somewhere, particularly if there are likely highly complicated engineering reasons why a new OS won't run on a certain line of machines, and also since you're only shutting out less than 10% (and a very vocal but minor 10%) of your users.