[OS X TeX] 64-bit binaries in TeXLive 2010

[Michael Hanson]

On Dec 4, 2009, at 10:54 PM, David Watson wrote:

> The only strictly 32-bit Intel machines that I know of from Apple  
> are the original MacBook Pros that have the "Core 2" label.
> Everything since has been 64-bit capable, even if Apple hasn't made  
> it a priority to exploit that fact before Snow Leopard.

While admittedly a minor point in this debate, I believe the situation  
is not quite that simple.

Early Intel-based Macs used "Core Solo" or "Core Duo" processors.   
Those are 32-bit, so Macs with them do not support 64-bit anything.   
Early Intel-based iMacs, MacBookPros and Mac minis all used one of  
these processors, I believe.

Later Intel-based Macs use "Core 2 Duo" or "Quad-Core Xeon"  
processors.  Those are 64-bit, and with Mac OS X 10.5 (Leopard) and  
10.6 (Snow Leopard) they can run 64-bit applications.  Not all support  
a 64-bit kernel, however.  For example, I'm reasonably certain that  
the currently-shipping Mac mini and MacBook do not support the 64-bit  
kernel (although finding information to confirm on Apple's web site  
seems difficult), although they will support 64-bit applications -- as  
will PPC G5 processors with OS X 10.5.  To see if your own Intel-based  
Mac supports the 64-bit kernel, type the following at a command prompt  
in Terminal.app (assuming 10.5 or later):

ioreg -l -p IODeviceTree | grep firmware-abi

If you see "EFI64", then your Mac supports the 64-bit kernel;  
otherwise it does not.  Again, any Mac with a 64-bit processor should  
still be able to run 64-bit applications under OS X 10.5 or 10.6,  
regardless of whether the kernel is 32- or 64-bit.

Hope that helps,
Mike