Is WinXP Pro 64-Bit Edition a True 64-Bit OS?

[Santosh Kumar]

Does Microsoft Windows XP Professional 64-Bit edtion support true 64-Bit processing (i.e. utilizing the full 64-bit CPU registers for computiations) in hardware as avaialable with the AMD Athlon64 and Opteron processors?

Or (as alleged by Intel to me over the phone) not a true 64-Bit OS in that it only supports 64-bit memory extensions (i.e. what Intel offers with their EM64T) but treats a 64-Bit processor such as the AMD Athlon64 (or even the Intel Itanaium / Intanium 2) as 32-bit processors?

Santosh Kumar

 

[NoNoBadDog!]

Intel was lying to you.

Microsoft Windows XP Professional x64 Edition is a 64 bit OS that will use the registers allocated to 64 bit, but will also run in legacy mode, running 32 bit software in 32 bit WOW mode.

There are significant differences between the Intel EM64T and AMD Athlon 64 processors.

You can research it yourself, but to make a long story short, AMD is currently far ahead of Intel in the 64 bit processor game. Intel still hobbles their EM64T processors to either a 533 or 800 MHz front side bus, as opposed to AMd which puts the memory controller on the processor chip and uses Hypertransport to handle communications between the processor and the AGP/RAM/PCI-E busses. This Hypertransport is a high-speed parallel communications protocol that is nominally 2GHz, much faster than anything Intel has to offer. Intel also insisted on including the worthless Hyperthreading on their EM64T chips. In everyday usage, Hyperthreading is a waste.

I suggest you do a little on-line research, and you will see that clearly AMD is the best choice.

NOTE: To all the whining Intel Fanboys - - don't even bother posting your replies, as they will be ignored. I used to only buy Intel procs, until they stopped being a leader and an innovator in the field. My AMD Athlon64 based computers run rings around anything Intel makes, and that is OOB.

Bobby


Does Microsoft Windows XP Professional 64-Bit edtion support true 64-Bit processing (i.e. utilizing the full 64-bit CPU registers for computiations) in hardware as avaialable with the AMD Athlon64 and Opteron processors?

Or (as alleged by Intel to me over the phone) not a true 64-Bit OS in that it only supports 64-bit memory extensions (i.e. what Intel offers with their EM64T) but treats a 64-Bit processor such as the AMD Athlon64 (or even the Intel Itanaium / Intanium 2) as 32-bit processors?

Santosh Kumar

 

[Charlie Russel - MVP]

Yes, full 64-bit registers. About the only thing that you could complain
about is that at this point it doesn't use a full 64-bits of address space
(do the math, that would be well beyond the 16 Terrabytes that it does use.)
And that's not likely to be a limitation for a while yet.

I've done quite a bit of research on this, including talking to people with
access to future versions of chips from both companies. Each processor has
some places where it's better, some where it's worse. Personally, I really
like the NUMA architecture that you get in a multi-Opteron environment
because of the HyperConnect. But then Intel seems to be able to squeeze a
good deal more cache directly on the chip.

 

[Ken Zhao [MSFT]]

Hi Santosh,

Thank you for your posting and thanks for Bobby's information!

It seems that you have some concerns of hardware in Windows XP Professional
x64 Edition.

Based on my knowledge, first of all, Microsoft Windows XP Professional x64
Edition is a true 64-bit OS.

As far as I know, currently supported processors include the following:
AMD? Athlon? 64 (FX)
AMD? Opteron?
AMD? Turion?
Intel? Xeon? with Intel EM64T support
Intel? Pentium? 4 with Intel EM64T support

The x64 processor architecture allows for native execution of 32-bit code
with no emulation overhead required. WOW64 is the 32-bit Windows emulation
layer on 64-bit Windows, and provides compatibility with 32-bit Windows
applications. The WOW64 subsystem enables 32-bit programs to run without
modification on the x64-based versions of Windows Server 2003 and of
Windows XP Professional x64 Edition. The WOW64 subsystem does this by
creating a 32-bit environment on the x64-based versions of Windows Server
2003 and of Windows XP Professional x64 Edition. For more information about
the WOW64 subsystem, see the "Running 32-bit Applications" topic in the
64-Bit Windows section of the Microsoft Platform SDK documentation. To view
this document, visit the following Microsoft Web site:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win64/win64
/running_32_bit_applications.asp

In addition, there are some differences between Itanium and x64 Edition
Versions:
1. Itanium? systems offer a highly scalable 64-bit platform that delivers
industry-leading performance for mission-critical, high-end systems.
2. Itanium? systems can run 32-bit code without recompiling, but require
hardware or software emulation for 32-bit processes. The x64 hardware can
run 32-bit operating systems in native mode without emulation.
3. Itanium? operating systems do not support multimedia features. The x64
Edition operating systems offer near-feature parity with current x86
desktop and enterprise environments.
4. Neither the Itanium? platform nor the x64 platform support 16-bit
application code.

For product information about Microsoft Windows XP Professional x64
Edition, visit the following Microsoft Web sites:
http://www.microsoft.com/windowsxp/64bit/default.mspx

Exploring Windows XP Professional x64 Edition
http://www.microsoft.com/windowsxp/using/64bit/russel_exploringx64.mspx

Overview of the compatibility considerations for 32-bit programs on 64-bit
versions of Windows Server 2003 and Windows XP
http://support.microsoft.com/kb/896456

Changes to Functionality in Microsoft Windows XP Professional x64 Edition
http://www.microsoft.com/technet/prodtechnol/winxppro/64bit/cifx64.mspx

For more information about device drivers for x64 platform, you may refer
to the following links:
http://www.planetamd64.com/

For more information about the 64-bit processor of AMD and Intel, please
refer to the links:
http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_9331,00.htm
l

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

Hope the information is helpful.

Thanks & Regards,

Ken Zhao

Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security

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--------------------
| From: "Santosh Kumar" <[email protected]>
| Subject: Is WinXP Pro 64-Bit Edition a True 64-Bit OS?
| Date: Thu, 2 Jun 2005 21:27:53 -0700
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|
| Does Microsoft Windows XP Professional 64-Bit edtion support true 64-Bit
processing (i.e. utilizing the full 64-bit CPU registers for computiations)
in hardware as avaialable with the AMD Athlon64 and Opteron processors?
| Or (as alleged by Intel to me over the phone) not a true 64-Bit OS in
that it only supports 64-bit memory extensions (i.e. what Intel offers with
their EM64T) but treats a 64-Bit processor such as the AMD Athlon64 (or
even the Intel Itanaium / Intanium 2) as 32-bit processors?
| Santosh Kumar
|

 

[Santosh Kumar]

The people I spoke to at Intel were at Pre-Sales Technical Support.

They told me that only "Longhorn" (the next version of Windows) will be the true 64-bit OS with true 64-bit processing.

And when I called Microsoft Tech Support, even they didn't seem to know very much. Couple of the Microsoft Tech Support Reps (who I assume didn't know very much) seemed to agree with Intel... but probably because they simply did not know.

It's too bad that misinformation is not illegal (or enforced if it is)....

Santosh Kumar

Its a full 64bit OS. Not sure who you spoke to at Intel but they are wrong.

Intel was lying to you.

Microsoft Windows XP Professional x64 Edition is a 64 bit OS that will use the registers allocated to 64 bit, but will also run in legacy mode, running 32 bit software in 32 bit WOW mode.

There are significant differences between the Intel EM64T and AMD Athlon 64 processors.

You can research it yourself, but to make a long story short, AMD is currently far ahead of Intel in the 64 bit processor game. Intel still hobbles their EM64T processors to either a 533 or 800 MHz front side bus, as opposed to AMd which puts the memory controller on the processor chip and uses Hypertransport to handle communications between the processor and the AGP/RAM/PCI-E busses. This Hypertransport is a high-speed parallel communications protocol that is nominally 2GHz, much faster than anything Intel has to offer. Intel also insisted on including the worthless Hyperthreading on their EM64T chips. In everyday usage, Hyperthreading is a waste.

I suggest you do a little on-line research, and you will see that clearly AMD is the best choice.

NOTE: To all the whining Intel Fanboys - - don't even bother posting your replies, as they will be ignored. I used to only buy Intel procs, until they stopped being a leader and an innovator in the field. My AMD Athlon64 based computers run rings around anything Intel makes, and that is OOB.

Bobby


Does Microsoft Windows XP Professional 64-Bit edtion support true 64-Bit processing (i.e. utilizing the full 64-bit CPU registers for computiations) in hardware as avaialable with the AMD Athlon64 and Opteron processors?

Or (as alleged by Intel to me over the phone) not a true 64-Bit OS in that it only supports 64-bit memory extensions (i.e. what Intel offers with their EM64T) but treats a 64-Bit processor such as the AMD Athlon64 (or even the Intel Itanaium / Intanium 2) as 32-bit processors?

Santosh Kumar

 

[Yves Leclerc]

Intel's 64 bit chips are the ones "emulating" 64 bit processors. AMD 64s when using Windows XP 64bit, is the true 64bit OS setup.


Does Microsoft Windows XP Professional 64-Bit edtion support true 64-Bit processing (i.e. utilizing the full 64-bit CPU registers for computiations) in hardware as avaialable with the AMD Athlon64 and Opteron processors?

Or (as alleged by Intel to me over the phone) not a true 64-Bit OS in that it only supports 64-bit memory extensions (i.e. what Intel offers with their EM64T) but treats a 64-Bit processor such as the AMD Athlon64 (or even the Intel Itanaium / Intanium 2) as 32-bit processors?

Santosh Kumar

 

[Paul Smith]

They told me that only "Longhorn" (the next version of Windows) will be
the true 64-bit OS with true 64-bit
processing.

And when I called Microsoft Tech Support, even they didn't seem to know
very much. Couple of the
Microsoft Tech Support Reps (who I assume didn't know very much) seemed to
agree with Intel... but
probably because they simply did not know.

I don't believe any of them seem to realise that Microsoft have just shipped
x64 Edition.

I hope Microsoft didn't just spend all that time redeveloping a 32-bit OS.
Hey if it was a 32-bit OS all our drivers would still be working. ;-)

--
Paul Smith,
Yeovil, UK.
http://www.windowsresource.net/

*Remove 'nospam.' to reply by e-mail*

 

[Guest]

I totally agree! my AMD ATHLON 64 is swish swish swish! click and the program
comes out in a flash! really fast. When i went to an intel powered pc wow, i
got impatient! AMD was relaly smart to put the memory controller on the chip,
saves lots of time i guess! now i really wonder how well windows 64bit will
do with me!

 

[Guest]

x64 OS contain a bunch of 32-bit binaries and even some 16-bit (showing
MS-DOS 16 in the version sig. verifier tool), yet I suspect what was most
critical for 64-bit significance was ported by RTM.
As far as IA64 (Itanium), do a find "zzzz" 5GB.txt in a 5GB file, and then
do the same under x64, just to see who has the true 64-bit OS...

 

[James Park]

I'm seeing this being said in a lot of places. I've also read that AMD isn't
a "real" (whatever that means) 64-bit processor either. I've yet to read
anything from a credible source. The closest thing I've seen to one is a
Windows Server guy saying that AMD's implementation was ahead of Intel's
(though he didn't go into specifics). If anybody could point me to
definitive read, that'd be great.

 

[Guest]

Santosh,

Do some research on a function called "thunking", It was originally
developed by Microsoft to allow 32 bit programs to function correctly with
some of the 16 bit interfaces for Windows 95. (Actually WfW 3.11 was the
first to use it).

Intel may be referring to the fact that several functions in x64 use
thunking and work within the WOW64 to complete their actions.

Several of the libraries used on my ATI AIW Radeon 9600 on x64 are thunked.

This may be why Intel is saying its not a "true" 64 bit OS as compared to
Solaris, Linux64 or AIX.

MS took alot of static when they called Win95 a 32 bit OS, when actually
only about 30 to 40 percent of it was actually functioning at a 32 bit level.
Win98 it moved up farther and WinME even more. How much thunking is actually
required on x64 to function normally has not been tested.

 

[Paul Nutt]

I totally agree! my AMD ATHLON 64 is swish swish swish!

Not that there's anything wrong with that!

 

[Guest]

I have a NUMA question for you. There is a disagreement here over whether the
32bit version of XP Pro is NUMA aware. Or is it just the 64bit version? Thanx!