Some answers re: XP Home and mlutiple CPUs 8 replies

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C38368

...burning angel wings to dust

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14th February 2004

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#1 13 years ago

First off, this is in response to carl4286's thread entitled "do you need XP Pro for a dual core CPU?" Second, I hope you all appreciate what I went through to get these answers: I used a spare WD800JB I had sitting around with a fresh installation of SUSE Linux Pro 9.1 on it. Being as I didn't want to sit around forever waiting for a full format, I had the Windows installer do a quick format. Big mistake. For those who don't know, there's a bunch of info in a drive's boot sector and partition tables that doesn't really need to be there (that is, an OS doesn't need any of it to boot). But M$, in thei infinite wisdom, decided to make Windows nearly unbootable if any of that extra info wasn't pristine and untouched. I've had this happen a few times: at first it was when I used Linux to repartition a Windows-bearing partition (this required chkdsk every time I did it). This time around, however, Windows would not boot either from the CD or HDD. So I left for the shop annoyed. When I got home I decided to reinstall SUSE and use it to blow away the Window partition, then reinstall Windows. Guess what I found? Installing SUSE let me boot into Windows and finish the installtion. Yeah, I just love M$ roll%20eyes%20%28sarcastic%29.gif At any rate, here's the hypothesis from today: M$ considers physical packaging in determining if it works or not. That is to say that you could have a 24-core CPU, and XP Home would recognise all 24 cores. But two single core processors won't work: it'll only recognise one core. Actual results: Booting into WinXP Home with HT enabled showed... TWO utilisation graphs in Task Manager. Device Manager listed four CPUs, but the OS was obviously only using either a single (HT-enabled) CPU, or was ignoring HT and using both chips. So I rebooted and disabled HT. XP Home now showed only a single utilisation graph in Task Manager, and listed two CPUs in Device Manager. Conclusion: This supports the assertation that M$ only considers discrete CPUs (in discrete sockets). Thus, a Pentium D used under XP Home should result in two physical cores being used. Similarly, a Pentium Extreme Edition should show four cores (two physical, two logical), even under XP Home.




Agentlaidlaw

Pie

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21st February 2005

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#2 13 years ago

Then why does M$ say you need pro to use more than 2 processors? But wait never mind its M$..........




C38368

...burning angel wings to dust

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#3 13 years ago

Because you do need Pro to use more than two physical sockets (you also need Pro to use two physical sockets, period). Did I not make it clear when I said that Home was only using one processor, despite the fact that it recognised two?




*The.Doctor

Trust me, I'm a Doctor

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25th November 2003

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#4 13 years ago
C38368Conclusion: This supports the assertation that M$ only considers discrete CPUs (in discrete sockets). Thus, a Pentium D used under XP Home should result in two physical cores being used. Similarly, a Pentium Extreme Edition should show four cores (two physical, two logical), even under XP Home.

Thanks for clearing that up C3, that info would be very helpful for anyone looking at a Pentium D and wondering if they can use XP home. smilie.gif




carl4286

Revenge was here.

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14th December 2004

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#5 13 years ago

Thanks C38368. Sorry you had to go through all of that, but you saved me (well, my friends family) $60 and uncovered some useful information about XP Home.... maybe this should go in the Knowledge Base thread so that all your hard work can be put to use a little more. So thanks again, and sorry you had to put yourself through that.




C38368

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#6 13 years ago
carl4286Thanks C38368. Sorry you had to go through all of that, but you saved me (well, my friends family) $60 and uncovered some useful information about XP Home.... maybe this should go in the Knowledge Base thread so that all your hard work can be put to use a little more. So thanks again, and sorry you had to put yourself through that.

No worries; if nothing else, it's just another notch in the belt smilie.gif I just hope that I'm right! EDIT~ I'd actually vote to not add this to the KB just yet, if only because it's predicated on past M$ behaviour. I haven't seen Home paired with Smithfield IRL yet, so I can't say beyond the shadow of any doubt that it's correct. I've just got a pretty solid body of evidence to suggest that it is.




Kilobyte

What does the Fox say?

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23rd November 2002

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#7 13 years ago
C38368I hope you all appreciate what I went through to get these answers:

I do appreciate that info. Saves me the trouble of having to do it as well. :D

I can understand what you had to go through. I've learned to always do a full format. I just did not have a copy of XP Home around to test it. Then, even though I do have several Dual systems, I do not have any Dual Core systems, or P4s with HT. So I had it planned for much later...

I really appreciate your info, it saves a lot of work.




C38368

...burning angel wings to dust

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#8 13 years ago
Monster_userI do appreciate that info. Saves me the trouble of having to do it as well. :D I can understand what you had to go through. I've learned to always do a full format.

Ironically, my normal procedure does involve a full format. Figures that the one time I try to slip by without it... *shrug* Glad to help. I think I'll install Gentoo next smilie.gif




Agentlaidlaw

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#9 13 years ago
C38368Because you do need Pro to use more than two physical sockets (you also need Pro to use two physical sockets, period). Did I not make it clear when I said that Home was only using one processor, despite the fact that it recognised two?

Sorry it's late for me and i'm half sleep and I only just skimmed through it. Sorry about that.