Will the late 09 iMac 27" boot Lion with 64-bit kernel?

[joelovesapple]

Anybody know if this is the case? Anyone on the dev preview who can tell me their stories?

Thanks. It's certainly not a turn-off if I won't be able to, but is interesting if I could.

[BigJohno]

I boot 64 kernel on my i7 09 model with snow leopard so I don't see why lion wouldn't be able too.

[joelovesapple]

Do you have to 'tell' it to do so or does it do it automatically?

[PurrBall]

It boots the 64-bit kernel by default on my early 2009 iMac, so I see no reason yours shouldn't.

[qacjared]

Anybody know if this is the case? Anyone on the dev preview who can tell me their stories?

Thanks. It's certainly not a turn-off if I won't be able to, but is interesting if I could.

Snow Leopard can do that....

http://support.apple.com/kb/HT3770

[joelovesapple]

Thanks!

[Gene S]

What was the answer? I have the same question.

With 10.6 is could boot to 64bit, but it didn't do it automatically, you had to hold down the numbers 6 & 4 during boot up.

Even that support link, 2 posts up says it is capable, but only 2011 models boot to it by default.

How does 10.7 behave?

[Strategy]

You can use the command uname -a in terminal to see what kernel its using.

RELEASE_i386 i386 is 32bit and RELEASE_X86_64 x86_64 is 64bit.

Im running a hackintosh setup with a core i5 and it defaulted to 32 bit.

[Draeconis]

Anybody know if this is the case? Anyone on the dev preview who can tell me their stories?

Thanks. It's certainly not a turn-off if I won't be able to, but is interesting if I could.

Lion boots into 64bit by default now on all capable machines.

You can use the command uname -a in terminal to see what kernel its using.

RELEASE_i386 i386 is 32bit and RELEASE_X86_64 x86_64 is 64bit.

Im running a hackintosh setup with a core i5 and it defaulted to 32 bit.

Add 'arch=x86_64' to the kernel flags in /Library/Preferences/SystemConfiguration/com.apple.Boot.plist, that'll force boot that 64bit kernel.