I'm running Lion on a late 2006 iMac!

[PhyrePhox]

I believe this limitation applies only to this particular build of 10.7, IMHO all C2D-equipped macs WILL be supported in final build.

It's really weird Dewroo is able to run 64bit kernel with his 5,1 iMac. Here are my specs from System Profiler:

Model Name: iMac
Model Identifier: iMac5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 3 GB
Bus Speed: 667 MHz
Boot ROM Version: IM51.0090.B09
SMC Version (system): 1.9f4

I'm running the same model iMac. Also unable to boot from external USB/SATA drive. However, when I hold down the option key at boot to select a different startup volume, there are three choices: my internal drive, the Lion external volume that doesn't work, and a mystery "Recovery" volume, that will boot!
It boots to (presumably) Lion, although no proper Finder: I get a window with choices to restore from TM, reinstall Lion (won't work), use Safari to get help online (works!), use Disk Utility, use Terminal (several commands I tried don't work), or choose a new Startup volume.
So, Lion boots, but only in Recovery. Even more frustrating than not working at all. Seems like it's something we can get around, eventually. Or, support for 32-bit EFI Macs will come later on?

 

[Dewroo]

I doubt that 32bit Macs will work in the future. it makes sense for apple to push forward like they did with the Power PC processors. however, i'm sure later on there will be workarounds to install Lion on older intel systems

 

[PhyrePhox]

To clarify: my iMac is a 64-bit Mac. However, the EFI is 32-bit. That seems to be the distinction between supported and unsupported Macs with this build of Lion: 64-bit EFI Macs are supported, 32-bit EFI Macs are not.
Core 2 Duo is the oldest 64-bit Intel CPU, and Lion is not supported at all on (pre-C2D) 32-bit Macs.

 

[mcdermd]

It doesn't matter the year, if it has a Core 2 Duo, it will run Lion. The install notes were likely referring to the Core Duo '06 models.

Like the iMac folks, I also cannot get Lion to install or boot on a Mac mini that was upgraded from 1.5GHz Core Solo to 2.16GHz Core 2 Duo. There is more going on than a simple CPU check.

I think PhyrePhox is on the right path with the 32/64 bit EFI distinction. The only hitch there is the early C2D MacBooks. Didn't they have 32-bit EFI also?

 

[PhyrePhox]

Like the iMac folks, I also cannot get Lion to install or boot on a Mac mini that was upgraded from 1.5GHz Core Solo to 2.16GHz Core 2 Duo. There is more going on than a simple CPU check.

I think PhyrePhox is on the right path with the 32/64 bit EFI distinction. The only hitch there is the early C2D MacBooks. Didn't they have 32-bit EFI also?

I remember a lot of discussion about 32/64 bit kernel, EFI, extensions, etc. when SL shipped. I'm sure someone put together a reference for which C2D has which EFI. I do remember that at the time, laptops were all excluded from running the 64 bit kernel, but I don't recall if that was an EFI issue.

Also, I repartitioned the internal drive and installed Lion DP there to see if it had anything to do with being on an external drive, but it still won't boot. And yes, I tried holding Option-Cmd-64 at the last boot of SL before installing Lion.

 

[PhyrePhox]

This person's explanation made the most sense:
http://www.ahatfullofsky.comuv.com/English/Programs/SMS/SMS.html
Perhaps Apple hasn't enforced the need for 64-bit kernel extensions until now. This still doesn't answer the question of whether laptops with C2D and 64-bit EFI will run Lion DP, or whether these limitations will persist past this built, or into the GM.

 

[smc333]

Core 2 Duo is the oldest 64-bit Intel CPU, and Lion is not supported at all on (pre-C2D) 32-bit Macs.

Perhaps the oldest 64-bit Intel chip in Macs, but there were EM64T compatible Pentium 4 chips...

 

[PhyrePhox]

Perhaps the oldest 64-bit Intel chip in Macs, but there were EM64T compatible Pentium 4 chips...

Point taken, but irrelevant here: we aren't discussing hackintoshes.

 

[JoeG4]

I was thinking if they redid the "about this mac" screen they'd at least stick the current IP address(es) in there. I guess making life easy for sysadmins is way too much to ask.

 

[racer]

Workaround!

Just followed this tip from CultofMac and it worked!

I managed to get the Lion preview running on a supposedly unsupported Macbook Core Duo from May 2006.

I installed Lion on a USB drive hooked up to a Mac Mini Core 2 Duo 2009, then removed /System/Library/CoreServices/PlatformSupport.plist and the same drive booted in the Macbook with no issues!

there might be some stricter restrictions in the future, but pretty good right now!

 

[PhyrePhox]

Just followed this tip from CultofMac and it worked!

I managed to get the Lion preview running on a supposedly unsupported Macbook Core Duo from May 2006.

I installed Lion on a USB drive hooked up to a Mac Mini Core 2 Duo 2009, then removed /System/Library/CoreServices/PlatformSupport.plist and the same drive booted in the Macbook with no issues!

there might be some stricter restrictions in the future, but pretty good right now!

View attachment 274355

Works for me too! Thanks racer!

 

[CyberBob859]

New Lion beta work with iMac 5,1?

Has anybody tried the new Lion beta drop on an iMac 5.1? Is this computer now supported?

 

[stooovie]

Yes it is. Works perfectly. Opening folders in Launchpad is slow.

 

[CyberBob859]

Yes it is. Works perfectly. Opening folders in Launchpad is slow.

Good to hear. Hopefully the speed issues will be corrected by the time Lion is officially released. I have a 5,1 iMac running Leopard, and was wondering if I should just put Snow Leopard on it or wait until Lion.

 

[John Johnson jr]

Hello!

On the first look my lat 2006 iMac is the same like the ones mentioned here before:

Model Name: iMac
Model Identifier: iMac5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 3 GB
Bus Speed: 667 MHz
Boot ROM Version: IM51.0090.B09
SMC Version (system): 1.9f4

But when I use the uname -v command in the console I get this:

Darwin Kernel Version 10.7.0: Sat Jan 29 15:17:16 PST 2011; root:xnu-1504.9.37~1/RELEASE_I386

So my iMac is not identical with Dewroo's.

I also tried the 32- or 64-bit Kernel Startup Mode Selector and it gives me the informations that the processor is 64bit ready but the rest is not as the attachment shows.

So what would that mean for me? And how can I change anything on my Mac—without taking any risks, of course.

 

[joelovesapple]

Just curious...

I have got a late 2009 27" iMac - is that a 64-bit EFI and will it run Lion ok?

Stupid question I know but it's one of the later C2D's...

 

[John Johnson jr]

Every Mac from 2007 and up will run Lion fine. The only machine in doubt is the late 2006 Core 2 Duo iMac.

 

[joelovesapple]

Every Mac from 2007 and up will run Lion fine. The only machine in doubt is the late 2006 Core 2 Duo iMac.

That's cool then - would be good if mine will run in 64-bit mode rather than 32-bit, just for the sake of it.

Funnily enough, I used to own the white 24" iMac and so would currently be worried if I still had it!

 

[qacjared]

Every Mac from 2007 and up will run Lion fine. The only machine in doubt is the late 2006 Core 2 Duo iMac.

Lion requires 2 GB of ram. Are we sure some of these machines just don't have enough ram? None of the late 2006 iMacs shipped with more than a gig.

 

[John Johnson jr]

All right then, I wasn't precise enough: Every Mac from 2007 and up is technically ready for Lion—but might need additional RAM. Which is easy for iMacs and Mac Pros but not so easy with older Mac Minis and MacBooks. Okay?

 

[PhyrePhox]

As someone pointed out earlier, the limitation was only on that build of Lion. Subsequent builds have worked fine on my iMac (DP2 and 3, anyway: I have DP4 but haven't installed it yet). The posted system requirements for Lion are for a 64-bit capable processor, which means all Core 2 Duos and up should work.

 

[TehEspaaK]

its not fair

I own a Core Duo Early 06 Model iMac but after buying, I replaced the processor with a 2.33GHz C2D Merom (after hours and hours of hard labour and nearly braking the screen)

Theoretically Lion should work but thanks a bunch Apple for failing on the old hardware again!
Might have to upgrade to an i7 Model now just so I could have it for a few years before Apple drops the updates for it too...

 

[John Johnson jr]

For anyone who is still interested: The final release of Lion is running fine on a late 2006 iMac (5,1). The EFI has not been changed to 64 bit in the updating process, it doesn't seem to be necessary.

 

[russellelly]

For anyone who is still interested: The final release of Lion is running fine on a late 2006 iMac (5,1). The EFI has not been changed to 64 bit in the updating process, it doesn't seem to be necessary.

How does performance compare to SL? I'm using a Late '06 6,1 , after the debacle of iOS4 on my iPhone 3G I don't want to upgrade if it compromises performance.

(PS - scary to think this Mac is nearly 5 years old - it still looks amazing and performs pretty damn well).

 

[John Johnson jr]

How does performance compare to SL? I'm using a Late '06 6,1 , after the debacle of iOS4 on my iPhone 3G I don't want to upgrade if it compromises performance.

I haven't tested it thoroughly yet but so far it looks really good. I have 3 GB of RAM, I must add.

(PS - scary to think this Mac is nearly 5 years old - it still looks amazing and performs pretty damn well).

Same here. Such a great machine.