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Groups > comp.sys.mac.hardware.storage > #1410

Re: mac OS issues with seeing, booting, and slow screens.

Cross-posted to 3 groups.

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In comp.sys.mac.hardware.storage David Empson <dempson@actrix.gen.nz> wrote:
> Andreas Rutishauser <andreas@macandreas.ch> wrote:

> > In article <hKadna1gefoVAQ7FnZ2dnUU7-fudnZ2d@earthlink.com>,
> >  ANTant@zimage.com (Ant) wrote:
> > 
> > > An old 13.3" MBP (mid-2012, 8 GB of RAM, Intel i7 CPU, etc.) couldn't
> > > see (boot up with Option key and in v10.8.5's System Preferences' 
> > > Startup) and boot off an external USB2 HDD with its mac OS Sierra 
> > > v10.12.2 that was installed in a 15" MBP (mid-2015). I had to download
> > > and install the almost 5 GB v10.12.3 into the same partition/drive to
> > > work. Note that I did not format it to install from scratch since it
> > > overinstalled and kept my previous accounts.
> > > 
> > > After finally booting up the old MBP from the same external USB2 HDD's
> > > mac OS v10.12.3, I noticed things felt slower like screen scrollings in
> > > Safari. Is it because of the older hardwares with the newer OS? I 
> > > thought Sierra was supposed to be faster and better on older hardwares?
> > > 
> > > Anyways, I was using an external HDD to see how Sierra perform on this
> > > old MBP.
> > 
> > the "error" probably was using incremetal updates on the MBP 15" 2015
> > from 10.12.0 to 10.12.2.
> > If you have the intention to use a disk to start different Macs, do not
> > use App Store to to update mac OS (they might be specific to the 
> > hardware). Use the downloads provided by Apple Support, i.e.
> > <https://support.apple.com/kb/DL1905>

> Sorry, but that is a myth. The ability of a macOS (or OS X) system to
> boot other Macs has nothing to do with whether updates were installed
> via App Store or manual download.

> The only factor which matters is whether the system is a model-specific
> custom build, i.e. the preinstalled software on a newly purchased Mac,
> and sometimes one or two subsequent updates of that software. These can
> be distinguished from the general release because they have a different
> build number (custom builds are always a four digit number after the
> letter; if the general build is also four digits then the custom build
> is a higher number).

> A general release of macOS will boot all supported models introduced
> prior to that version. It will NOT boot on a newly released model,
> because it doesn't recognise the model.

> A custom build for a new model usually will boot on older models. It has
> additions to support the new model (e.g. drivers for new hardware) but
> doesn't omit files required for older models. There may be rare
> occasions where support for older models is broken in a custom build, so
> it is best to play it safe and not try to use it on a different model.

> Once the OS has been updated to the point Apple has included support for
> the new model in the general release, then the updated system is
> identical on all models, and for all install methods (full install,
> manual delta or combo update, or App Store). It can boot all compatible
> models. If the build numbers are the same, the OS is the same.

> In cases where it takes Apple a couple of minor versions to integrate
> support for a new model into the general release, there will be a
> model-specific custom update on support.apple.com/downloads, and it will
> not be possible to use the general delta/combo update on that model. (I
> recall this happening a few times around 10.6.4, for example.)

> A major new OS version installed from the full installer is always the
> general release which supports all models introduced prior to that
> version (and sometimes coinciding with that version). Subsequent updates
> maintain that state, adding support for any newly introduced models
> which Apple has integrated into the general release.

> In this case, a Mid 2015 MacBook Pro would have originally shipped with
> a custom build of OS X 10.10.3, would probably have been on the general
> release when updated to to 10.10.4 and would certainly be on the general
> release when upgraded to OS X 10.11.x or macOS 10.12.x, or if either of
> those was installed on an erased drive.

> Therefore the inability of that 10.12.2 system to boot an older Mac is
> probably due to something having gone wrong with the cloning process
> resulting in a non-bootable drive, rather than missing support for the
> older model.

> I'd like to know how the 2015 Mac's internal drive was cloned to that
> USB drive, because whatever method was used did not work.

Actually, it wasn't a clone. I originalled installed mac OS v10.12.2 
into the external USB HDD with a 15" MBP (mid-2015). I was reusing this 
drive on an older 15" MBP (2012).


> Doing a full install on the drive fixed whatever the problem was.

Yeah with an install over the same drive (didn't erase/format it).


> As for the performance question, some slow downs may be due to the fact
> that the system is booting via USB, especially if it really is USB 2
> (the Mid 2012 MacBook Pro can do USB 3). USB 2 would be a bottleneck
> that would limit the drive performance compared to an internal hard
> drive, which would at least slow down booting and application launch,
> but would also slow down reading or writing cached data on disk, virtual
> memory swapping, etc.

Isn't 8 GB of RAM enough to not use the disk much?
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Thread

mac OS issues with seeing, booting, and slow screens. ANTant@zimage.com (Ant) - 2017-02-02 14:54 -0600
  Re: mac OS issues with seeing, booting, and slow screens. Andreas Rutishauser <andreas@macandreas.ch> - 2017-02-03 06:04 +0100
    Re: mac OS issues with seeing, booting, and slow screens. ANTant@zimage.com (Ant) - 2017-02-03 16:40 -0600
    Re: mac OS issues with seeing, booting, and slow screens. dempson@actrix.gen.nz (David Empson) - 2017-02-04 13:38 +1300
      Re: mac OS issues with seeing, booting, and slow screens. ANTant@zimage.com (Ant) - 2017-02-04 12:46 -0600
        Re: mac OS issues with seeing, booting, and slow screens. dempson@actrix.gen.nz (David Empson) - 2017-02-05 08:56 +1300
          Re: mac OS issues with seeing, booting, and slow screens. Alrescha <alrescha@gmail.com> - 2017-02-04 15:49 -0500

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