Dual processor ML370 shows as quad process in Win2k

[Zach Hoffman]

Our ML370 G3 which has dual Xeon 2.8 GHz processors is recognized by Windows 2000 Server as actually having quad (four) 2.8 GHz processors.

Does this have to do with the fact that these Xeon processors utilize hyperthreading and each processor is actually recognized as having two separate processors? We are baffled and are mainly concerned because of licensing issues (i.e. we buy a product which is only licensed for two processors and we are showing four).

The server has been up for a while now and there are now apparent problems with it. Even installing SQL Server 2000 recognizes the machines as having quad processors.

Any help would be greatly appreciated!

[Janine Bertolo · Accepted solution]

Hi Zach;

Yes, the hyperthreading feature of the processors is the reason for you seeing 4 processors.

A search of the forums content would result in several discussions on hyperthreading:

http://us-support2.external.hp.com/emse/bin/doc.pl/sid=da1c547309776c6f70?todo=search&searchtext=processor+number&searchcriteria=allwords&searchtype=SEARCH_FORUMS&searchcategory=ALL&rn=25&presort=date&x=29&y=10

You will most likely be able to find some helpful information there.

Cheers,

Janine

[David in Tennessee]

Turn off hyper-threading. Then, you won't see but one processor per Xeon.

To disable/enable Hyper-Threading requires a reboot.
Procedure for ML370G3 and perhaps other servers:

While the system is booting press key at the appropriate time
scroll down to Advanced Options with the arrow keys

scroll down to Processor Hyper-Threading with the arrow keys

scroll down to "Disabled" (or "Enabled" if turning Hyper-Threading back on)

(go back one screen)
(go back one screen)
(to continue the reboot)

[Juan Carlos Ramirez]

The new Intel XeonTM processors incorporate Intel's Hyper-Threading Technology, which makes one physical processor look like two logical processors to the OS and applications. These two 'logical' processors on a single physical processor can execute different tasks simultaneously using shared hardware resources. By allowing the processor to use on-die resources that would otherwise have been idle, Hyper-Threading Technology provides a performance boost on multi-threading and multi-tasking operations. Not all operating systems take advantage of the XeonTM Hyper-Threading features.

http://h18004.www1.hp.com/products/servers/technology/hyper-threading.html

[Juan Carlos Ramirez]

Intel suggests disabling HyperThreading on all WIn2K, NT, and prior operating systems. Only new operating systems include optimizations for HT Technology.

http://www.intel.com/support/platform/ht/os.htm

Microsoft says:
Microsoft expects performance to vary depending on the application, system configuration, and version of Windows that is used.

Although Windows 2000 is compatible with Hyper-Threading Technology, we expect customers will get the best performance from Hyper-Threading Technology using Windows .NET Server. This is because the Windows .NET Server Family is engineered to take full advantage of the logical processors created by Hyper-Threading Technology.

http://www.microsoft.com/windows2000/docs/hyperthreading.doc

For SQLServer
On a system with Intel HTT enabled, Microsoft requires only one license for each physical processor. Therefore, customers only need to acquire one processor license for each physical processor even though the software may count one physical processor as two logical processors.

http://www.microsoft.com/sql/howtobuy/SQLonHTT.doc