Installing Lion on a new MBA

The earliest version of OSX you can install is the version it comes with. Since Lion does not contain the drivers for the Ivy Bridge chipset you'll not be able to load it

I haven't tried it, but possible, because Apple has offers free upgrade for owner with Lion installed in their 2012 version to Mountain Lion. It seems, early batches has still Lion preinstalled.

Soundflunky said:

I'd like to buy a new Air (I'm currently using the 2010 model) but I'd also like to avoid having to use Mountain Lion (It has worsened the performance of every machine I installed it on, and adds nothing I'm that interested in).

Is it possible to erase the SSD and install an older OS than shipped on it?

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Soundflunky said:

I'd like to buy a new Air (I'm currently using the 2010 model) but I'd also like to avoid having to use Mountain Lion (It has worsened the performance of every machine I installed it on, and adds nothing I'm that interested in).

Is it possible to erase the SSD and install an older OS than shipped on it?

Click to expand...

Nope sorry Not possible. In fact, it's not even possible to install an older version of a certain version of OS X (For example, if a MacBook came with OS X 10.7.3, you will not be able to install anything before that… like 10.7.2) because it doesn't have the correct drivers for graphics etc

I don't understand why you'd want to install Lion though… just get Mountain Lion… it runs very smoothly. Actually my MBA runs Mountain Lion a lot better than Lion (Which it came with)

I concur, if performance is your concern, then do not worry. I have a Mid 2012 MBA came with Mountain Lion, and it is a fantastic performer.

I have 2011 MBA and it runs much better on Mountain Lion than it did with Lion.

Soundflunky said:

I'd like to buy a new Air (I'm currently using the 2010 model) but I'd also like to avoid having to use Mountain Lion (It has worsened the performance of every machine I installed it on, and adds nothing I'm that interested in).

Is it possible to erase the SSD and install an older OS than shipped on it?

Click to expand...

Mountain Lion will only worsen the performance of machines that are stuck with 2GB of RAM. Period. Even if you are rocking any Mac with 4GB of RAM, including the oldest generation of MacBook Pros that can run it, you will actually find that Mountain Lion is FASTER. That is...unless you have pre-existing software or hardware problems that have nothing to do with the installation of the OS itself.

That being said, you can wipe your machine and install Lion if you so desire. The current MacBook Airs originally shipped with a system-specific build of 10.7.4 before Mountain Lion came out (and then were thusly shipping with Mountain Lion) so as long as you can find and install either that specific build of 10.7.4 or a generic 10.7.5 Mac App Store version, you should be fine. Though again, I don't know why you'd want to. Any current MacBook Air will run Mountain Lion so much nicer than Lion.

maflynn said:

The earliest version of OSX you can install is the version it comes with. Since Lion does not contain the drivers for the Ivy Bridge chipset you'll not be able to load it

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Uh...Lion (with system specific builds of 10.7.4 and the retail version of 10.7.5) definitely contains drivers for all Mid 2012 MacBook Airs and MacBook Pros (including the 15" retina) and their Ivy Bridge chipsets. What it doesn't have is drivers for any 13" retina, any Late 2012 iMac or any Late 2012 Mac mini. Nor does it have drivers for any of the Early 2013 retinas. But the mid-2012 machines originally shipped with Lion, and the logic board part number has not changed since release. The only thing that has changed is that they now ship with a retail build of Mountain Lion preloaded and will allow you to use Internet Recovery with Mountain Lion rather than with Lion. Other than that, there's no difference.

Therefore, if the OP really wants Lion on that machine, then all he/she needs is a retail installer for 10.7.5 and they'll be golden.

Soundflunky said:

That's a lot of help. Thanks.

I've installed ML on a rMBP, a Mac mini and an MBA and they've all suffered for it, especially with Safari, which works great in Lion but is glitchy as heck in ML.

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You're in a very, very small minority. I've never heard of people experiencing worse performance with ML over Lion.

SpyderBite said:

You're in a very, very small minority. I've never heard of people experiencing worse performance with ML over Lion.

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My 2012 MBA shipped with Lion (I purchased one within about 1 week of the release), and I upgraded to ML a few months ago. My battery life dropped significantly, from 7-8 hours with "regular" use to 4-5 hours. I also notice that waking from "hibernate" is significantly slower... When I turn it on after being asleep for an hour or two, it takes about 5 seconds before anything responds and it allows me to type into the Password box.

I haven't really noticed any performance improvements either. Just my two cents.