Distinguishing Processors in Server Properties

I have a SQL 2005 64 bit Standard box running on Windows Server 2003.
It has 4 dual core processors (with hyperthreading) and I would like to
scale it back to 2 dual cores. When I look at the processors in server
properties, it lists:
CPU0
CPU1
etc...
My assumption is that 0-3 are all from the first CPU (1 * dual core *
hyper thread). But I do not want to assume, I want to know which
processors I am picking for use and I can not find any documentation on
how those names map. Does anybody know?
PTThe more I think about it, I am thinking SQL 2005 does not know the
details of the physical processors, and is just told by the OS that
there are X logical processors. Anyhow, I would still like to know.|||You are correct. SQL sees logical processors only. Plus, there aren't ane
"real" and "virtual" processors. They are all virtual. You have to turn
off hyperthreading at the BIOS level to get "real" processors.
--
Geoff N. Hiten
Senior Database Administrator
Microsoft SQL Server MVP
"Paul T." <weluvpaul@.hotmail.com> wrote in message
news:1163116200.511102.129730@.k70g2000cwa.googlegroups.com...
> The more I think about it, I am thinking SQL 2005 does not know the
> details of the physical processors, and is just told by the OS that
> there are X logical processors. Anyhow, I would still like to know.
>|||Paul
Check out this link - it provides an decent explanation
http://rentacoder.com/CS/blogs/real_life_it/archive/2006/04/28/477.aspx
--
Cheers
Bil
"Geoff N. Hiten" wrote:
> You are correct. SQL sees logical processors only. Plus, there aren't ane
> "real" and "virtual" processors. They are all virtual. You have to turn
> off hyperthreading at the BIOS level to get "real" processors.
> --
> Geoff N. Hiten
> Senior Database Administrator
> Microsoft SQL Server MVP
>
>
> "Paul T." <weluvpaul@.hotmail.com> wrote in message
> news:1163116200.511102.129730@.k70g2000cwa.googlegroups.com...
> > The more I think about it, I am thinking SQL 2005 does not know the
> > details of the physical processors, and is just told by the OS that
> > there are X logical processors. Anyhow, I would still like to know.
> >
>
>|||Inter recommends that HT is implemented such as:
They you have two physical processors. This will surface as 4 processors to the OS. So, the
processors are presented to the OS should be:
CPU0 - Phy CPU0
CPU1 - Phy CPU1
CPU2 - Phy CPU0
CPU3 - Phy CPU1
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
"Paul T." <weluvpaul@.hotmail.com> wrote in message
news:1163112570.239503.214220@.i42g2000cwa.googlegroups.com...
>I have a SQL 2005 64 bit Standard box running on Windows Server 2003.
> It has 4 dual core processors (with hyperthreading) and I would like to
> scale it back to 2 dual cores. When I look at the processors in server
> properties, it lists:
> CPU0
> CPU1
> etc...
> My assumption is that 0-3 are all from the first CPU (1 * dual core *
> hyper thread). But I do not want to assume, I want to know which
> processors I am picking for use and I can not find any documentation on
> how those names map. Does anybody know?
> PT
>|||You shouldn't worry about whch core maps to which socket. Each core is a real
processor, and there is not much you can or should do with that mapping. So
let's just call a core a physical processor. However, there is some
interesting issue with mapping a physical processor to a hyperthreaded (or
logical) one.
Ideally, you should be able to tell because BIOS assigns the first 'logical'
processor for each physical one before looping back to assign the second one
after it has gone through all the physical processors. This is all good.
However, Perfmon lists and numbers the logical processors differently. So you
could end up seeing CPU consumption on each alternate processor in Perfmon.
Microsoft has a little utility called htdump.exe that is distributed as part
of MPS Reports. This utility gives you the physical-to-logical mapping as
reported by Perfmon. Now, this was something we encountered about a year ago.
Things may have changed since then.
Linchi
"Paul T." wrote:
> I have a SQL 2005 64 bit Standard box running on Windows Server 2003.
> It has 4 dual core processors (with hyperthreading) and I would like to
> scale it back to 2 dual cores. When I look at the processors in server
> properties, it lists:
> CPU0
> CPU1
> etc...
> My assumption is that 0-3 are all from the first CPU (1 * dual core *
> hyper thread). But I do not want to assume, I want to know which
> processors I am picking for use and I can not find any documentation on
> how those names map. Does anybody know?
> PT
>sql