64-bit Windows Vista upgrade Question

[baduni]

Hi
I am running Windows XP SP2. My CPU is an Intel Core 2 Duo E6400.
When i follow the steps given by Microsoft below
( http://www.windowsmarketplace.com/content.aspx?ctId=396&tabid=1)
"PROCESSOR_ARCHITECTURE" comes up as "x86".

So is a Core 2 Duo CPU 32 Bit or 64 Bit CPU?

Thanks in advance.

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http://www.windowsmarketplace.com/content.aspx?ctId=396&tabid=1

Follow these steps to prepare for your 64-bit Windows Vista upgrade:
1) Confirm that your PC is capable of running 64-bit software.
1.Open the "System Properties" window
a.If your Start menu is configured for Classic Start menu, right-click the My Computer icon on your desktop, and click Properties.
b.If your Start menu is the Windows default Start menu, click the Start button, then right-click the My Computer icon in your Start menu, and click Properties.
2.Click the Advanced tab.
3.Click Environment Variables.
4.In the "System variables" list at the bottom of the Environment Variables window, look for a variable called "PROCESSOR_ARCHITECTURE". If your PC has a 32-bit processor, this variable will have a value of "x86". If it has a 64-bit processor this variable will have a value of "x64".If you are still unsure, please visit Microsoft.com or check with the manufacturer of your PC to determine if your system, applications, and devices are 64-bit capable. If you find your PC is not capable of running 64-bit software, you can still upgrade to a 32-bit edition of Windows Vista. Visit our Windows Vista 32-bit Showcase for more information.

 

[JetBlack69]

Core 2 Duo is a 64-bit processor, but it can run 32-bit applications as well.

 

[Lord Evermore]

Not sure why they give you those instructions. If you are using 32-bit Windows XP, then the processor IS running in x86 32-bit mode, even if it's capable of 64-bit. That variable tells the OS what instruction sets to use. If you were running 64-bit Windows XP it would show x64.

The Core 2 Duo line is 64-bit capable, it uses Intel's EM64T instruction set, which is compatible with AMD's AMD64 instruction set which was the first 64-bit x86.

However keep in mind that 64-bit driver and software support is still far less than 32-bit versions, and the only real benefit of 64-bit is the ability to use more than 4GB of memory.

 

[ch33zw1z]

So are Core2Duo's TRUE 64-bit, or does they still push it thru a 32-bit pipe?

 

[StopSign]

I believe it's not true 64-bit. The EM64T instruction set was something that Intel just tacked on to the P4 line to compete with Athlon 64.

 

[F1shF4t]

Originally posted by: ch33zw1z
So are Core2Duo's TRUE 64-bit, or does they still push it thru a 32-bit pipe?

Huh?

what is meant by 64bit cpu is that it has 64bit general purpose registers and can address 64bit memory addressing.

IA64 (or itanium) is as much a true 64bit as x86-64 it is just different architecture (i'm saying this is cause intel used to call it true 64bit which is just marketing hype, and prolly the reason why people still ask the question about cpus being true 64bit or not)

 

[xtknight]

Yes, the Intel Core 2 Duo is a true 64-bit processor running x64 architecture. It has GPRs 64 bits long, and all x64 processors also support running 32-bit code. This CPU only supports macro fusion in 32-bit mode so you may lose a bit of performance going to 64-bit in some cases.

 

[Lord Evermore]

Originally posted by: StopSign
I believe it's not true 64-bit. The EM64T instruction set was something that Intel just tacked on to the P4 line to compete with Athlon 64.

It's 64-bit in the same way that the Athlon 64 is. The 64-bit design is just a modification to the 32-bit x86 design, which is a modification of the 16 bit, which is a modification of the 8 bit. The instruction set architecture (x86) can be run on any bit-size processor designed for it. EM64T is just Intel's compatible version of AMD's design.

 

[JackBurton]

Hey Lord, doesn't Vista 64bit remove the 2GB memory per process limitation older 32bit MS OSes had? If so, that could be a big plus for Vista 64.

 

[baduni]

Thanks guys.
Stupid M1croS0ft. They should just list the current CPUs and say this CPU is 64 bit and this is not.

 

[Lord Evermore]

Not MS's responsibility to make sure you know what your hardware is capable of. And there could at any time be a new CPU available making their list outdated. Better would just be for them to properly document how to figure it out.

JackBurton: the 2GB limit is a 32-bit issue, Vista can't fix that, only using a 64-bit OS can. There's the /3GB option but that's available in XP too, and isn't always a good idea. Even games that people think they need 2GB for aren't actually using 2GB for a single process right now though.

 

[JackBurton]

Originally posted by: Lord Evermore
JackBurton: the 2GB limit is a 32-bit issue, Vista can't fix that, only using a 64-bit OS can. There's the /3GB option but that's available in XP too, and isn't always a good idea. Even games that people think they need 2GB for aren't actually using 2GB for a single process right now though.

That's what I thought. Thanks man!