Does the MacBook have an EM64T enabled processor?

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Level 1

95 points

Does the MacBook have an EM64T enabled processor?

I am curious whether or not the Intel processor inside the MacBook is EM64T enabled. I am not talking about software or OS support, but am interested to find out if anyone knows of any links on Apple.com that reference the status of EM64T on the actual hardware. Here is the Intel.com reference for EM64T:

http://www.intel.com/technology/64bitextensions/

Thanks in advance.

MacBook 1.83ghz, Mac OS X (10.4.7)

Posted on Aug 8, 2006 12:53 PM

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Answer 1

Kappy

Level 10

362,007 points

Aug 8, 2006 1:31 PM in response to tfurr0ws

The Core Duo CPU in the MacBook, MacBook Pro, and Intel Mac and Mini is a 32 bit processor, not 64 bit. Nor is the MacBook a 64 bit design. Presently only the new MacPro and XServe are 64 bit computers with 64 bit CPUs. Also, Tiger only supports 64 bit software at the Unix level.

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Answer 2

tfurr0ws Author

Level 1

95 points

Aug 8, 2006 2:08 PM in response to Kappy

Unfortunately, this doesn't help me out, as I am looking for a link on apple.com or intel.com that states specifically that the MacBook does or does not have EM64T support at the hardware level.

I'd love to take people's word, but knowing that Intel doesn't make any Dual-core CPUs without EM64T, I find it hard to believe that the MacBook's processor doesn't have it. I don't have proof either way, and would love to see some.

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Answer 3

Kappy

Level 10

362,007 points

Aug 8, 2006 2:38 PM in response to tfurr0ws

Well, since you appear to know the answer to your question, what's the point of the question?

As best I can tell from the document you referenced only the 64 bit processors have EM64T. That document specifically mentions Xeon and Itanium. It does not appear to mention the Core Solo or Core Duo CPUs used in the Intel Macs other than the new Mac Pro (which does use the Xeon processors.) Furthermore, the note at the bottom of the page says, "Intel® EM64T requires a computer system with a processor, chipset, BIOS, operating system, device drivers and applications enabled for Intel EM64T. Processor will not operate (including 32-bit operation) without an Intel EM64T-enabled BIOS." The MB, MBP, Intel iMac and Mini would not meet these requirements. According to other Intel documentation the supported processors are the Pentium 4 6xx series.

Further, if I understand the Intel notation the Core Duo is an IA-32 device - Intel Architecture-32 bit. The following table appears to also classify the Core Duo as a 32 bit processor.

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Answer 4

tfurr0ws Author

Level 1

95 points

Aug 8, 2006 2:50 PM in response to Kappy

Actually, I did not know the answer, and in fact it appears that the answer I thought was right was wrong. Here is what I found:

1. Searched Intel.com and found the following table. EM64T support (yes/no) was missing (first hint that EM64T wasn't there)

http://www.intel.com/products/processornumber/body_viewcore.htm

2. I downloaded and ran CPU-Z in WINE (darwine) to get the CPUID values (which are low-level, easty to access and worked fine in WINE, as expected). I took a screenshot with Apple Shift3 and posted it here:

http://img333.imageshack.us/img333/7854/picture1xt3.png

3. I searched in google for Yonah+EM64T... apparently there was some confusion as to whether or not EM64T would be included...

4. Found Wikipedia article on the subject.

"EM64T (Intel x86-64 extensions) is not supported by Yonah. However, EM64T support is planned for Yonah's successor, Core 2, code-named Merom."

http://en.wikipedia.org/wiki/Intel_Core

5. Problem solved as "officially" as possible, without being able to find a link on apple.com or intel.com unfortunately 😟 I would still love to see apple or intel state specifically that Yonah T2400 does not support EM64T.

Thanks!

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Answer 5

Kappy

Level 10

362,007 points

Aug 8, 2006 2:58 PM in response to tfurr0ws

Yes, the Core 2 Duo processors, of which the Xeon is one, are supposed to be 64-bit CPUs (well, of course Xeon is.) I don't recall if Merom is a Core 2 Duo or another in the Core Duo family. The table I referenced in my previous reply did not list Merom at all nor any other of the new Core 2 Duo family other than Xeon.

Glad you have your answer.

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