Can an 32-bit OS run on multiple 64-bit CPU cores?

[FlatAssembler]

Hey, guys!

So, I've tried to implement a MergeSort algorithm in standard C++11 that will run on as many CPU cores simultaneously as it can. You can see the source code here. However, I've noticed that if I run that program on 32-bit Windows 10 on my laptop (I have 32-bit Windows 10 and 64-bit Oracle Linux), here is the 32-bit Windows executable, it always claims to be running in a single thread. On the other hand, if I run it on 64-bit Linux on that same computer, it usually claims to run in 15 threads. What do you think is going on here? The processor in my laptop is Intel Core i5, 8th Generation. I know that running a 32-bit OS prevents the modern processor from using some registers, but I fail to see how it can possibly prevent it from using multiple CPU cores. The OS, these days, usually detects other CPU cores using ACPI, and it obviously shouldn't matter if the OS is 64-bit or 32-bit. But, apparently, it somehow does.

[Brian37]

Hey, guys!

So, I've tried to implement a MergeSort algorithm in standard C++11 that will run on as many CPU cores simultaneously as it can. You can see the source code here. However, I've noticed that if I run that program on 32-bit Windows 10 on my laptop (I have 32-bit Windows 10 and 64-bit Oracle Linux), here is the 32-bit Windows executable, it always claims to be running in a single thread. On the other hand, if I run it on 64-bit Linux on that same computer, it usually claims to run in 15 threads. What do you think is going on here? The processor in my laptop is Intel Core i5, 8th Generation. I know that running a 32-bit OS prevents the modern processor from using some registers, but I fail to see how it can possibly prevent it from using multiple CPU cores. The OS, these days, usually detects other CPU cores using ACPI, and it obviously shouldn't matter if the OS is 64-bit or 32-bit. But, apparently, it somehow does.

Corporate competition.

McDonald's and Burger King both sell burgers, and sure, the meet and buns are interchangeable, but they don't like the competition.

[Gawdzilla Sama]

"It appears to be in some kind of English." Steve Rogers

[FlatAssembler]

Hey, guys!

So, I've tried to implement a MergeSort algorithm in standard C++11 that will run on as many CPU cores simultaneously as it can. You can see the source code here. However, I've noticed that if I run that program on 32-bit Windows 10 on my laptop (I have 32-bit Windows 10 and 64-bit Oracle Linux), here is the 32-bit Windows executable, it always claims to be running in a single thread. On the other hand, if I run it on 64-bit Linux on that same computer, it usually claims to run in 15 threads. What do you think is going on here? The processor in my laptop is Intel Core i5, 8th Generation. I know that running a 32-bit OS prevents the modern processor from using some registers, but I fail to see how it can possibly prevent it from using multiple CPU cores. The OS, these days, usually detects other CPU cores using ACPI, and it obviously shouldn't matter if the OS is 64-bit or 32-bit. But, apparently, it somehow does.

Corporate competition.

McDonald's and Burger King both sell burgers, and sure, the meet and buns are interchangeable, but they don't like the competition.

Err... Are you sure you posted this in the right thread?

[Brian37]

Corporate competition.

McDonald's and Burger King both sell burgers, and sure, the meet and buns are interchangeable, but they don't like the competition.

Err... Are you sure you posted this in the right thread?

Yes. Computer and software companies have patents and copyrights on their products and have licencing agreements with each other, so not all software or hardware are interchangable. Just like a restaurant won't let you bring food in from another joint and eat it out in the open. 

I am not saying it is impossible to make the changes you want, but if you can't then one reason may be because of what I said above.

[FlatAssembler]

Err... Are you sure you posted this in the right thread?

Yes. Computer and software companies have patents and copyrights on their products and have licencing agreements with each other, so not all software or hardware are interchangable. Just like a restaurant won't let you bring food in from another joint and eat it out in the open. 

I am not saying it is impossible to make the changes you want, but if you can't then one reason may be because of what I said above.

My question was why does 32-bit Windows 10, if run on Intel Core i5 8th Generation, appear to run only on 1 core. If the processor was somehow modified to accept only certain OS-es, what I'd reasonably expect would be that it rejects free Linux, rather than proprietary Windows 10.

[Abaddon_ire]

Yes. Computer and software companies have patents and copyrights on their products and have licencing agreements with each other, so not all software or hardware are interchangable. Just like a restaurant won't let you bring food in from another joint and eat it out in the open. 

I am not saying it is impossible to make the changes you want, but if you can't then one reason may be because of what I said above.

My question was why does 32-bit Windows 10, if run on Intel Core i5 8th Generation, appear to run only on 1 core. If the processor was somehow modified to accept only certain OS-es, what I'd reasonably expect would be that it rejects free Linux, rather than proprietary Windows 10.

https://docs.microsoft.com/en-us/windows...sor-groups

So Win32 can't do it.

[FlatAssembler]

My question was why does 32-bit Windows 10, if run on Intel Core i5 8th Generation, appear to run only on 1 core. If the processor was somehow modified to accept only certain OS-es, what I'd reasonably expect would be that it rejects free Linux, rather than proprietary Windows 10.

https://docs.microsoft.com/en-us/windows...sor-groups

So Win32 can't do it.

So, if I understand you correctly, using multiple CPUs is no longer done using BIOS?

[Abaddon_ire]

https://docs.microsoft.com/en-us/windows...sor-groups

So Win32 can't do it.

So, if I understand you correctly, using multiple CPUs is no longer done using BIOS?

BIOS is only half the story. The OS must be written to do it also.

[BrianSoddingBoru4]

Just poking me head in to say I have no idea what you people are talking about, but I could do with a burger.

Boru