Does a 32bit OS realize it's running on a 64bit processor?

Say for example your running Windows Xp Pro, which is a 32bit OS, and your running on a 64bit processor like the Merom. Will the OS and Merom function any differently than if it were a Yonah, disregarding the change in frequency, bus speed, cache, efficiency etcetera?

Or try answering this- If I have some professional software that runs in XP Pro perfectly fine on a Yonah, can I pretty much assume it will run fine in XP Pro on the Merom, just faster, better and cooler?

 

It will run the same, but a little faster.

 

To answer your fisrt question, no Windows XP Pro would run just the same if it were on Yonah or Merom, if diregarding clock frequency etc.

To answer your second question, i would say yes. Programs aren't concerned about what the processors name is, they simply want the job doing as quick as possible. So, the prgram will utilise whatever the processor can offer, be it a larger cache or a faster clock speed.

 

If the OS is 32bit,then it will run as it would on any processor. Merom is a 23/64bit processor and so can run in both modes. It might be a little bit faster, but that would be due to the improvements to the core, not due to the presence of 64bit.

 

My concern was if that if a program ran without problems utilizing the dual core structure of a 32bit processor, would the structural changes of the 64bit dual core processor be anything that could upset --- anything. So if the Merom will run just as if it were a 32bit, except better- that is fantastic.

 

No x86 architecture cant tell the difference between a 64bit or 32bit. But the x64 can, thats the difference. When and only when the kernel can take advantage of the 64bits will you notice a difference. Otherwise its standard 32bit mode.

 

Nah, it'll run exactly the same. In 32-bit mode, it is 100% 32 bit, and the all 64-bit stuff is simply disabled. You get full, absolute, 100% compatibility, so no, it won't upset anything.

But also, it won't improve performance either. All 64 bit features aren't there, as far as the OS and programs running on it, are concerned.

 

I think what Zaz meant by 'It will run the same but faster' response is that it will run faster due to using Merom which is clock per clock a little faster then Yonah. Which is in response to the second question, not the first by kabooky.