Intel *SM users,
FYI, (and not 'on topic' strictly, but as the subject came up), anyone
running Windows 2000 or below on HyperThreading enabled processors
should, apparently, look into turning this off. Windows 2000 is not
HyperThreading aware (Windows .Net Server and 2003 are, however), in
that it does not know how to distinguish between physical and logical
processors. In this way, it does not balance jobs across physical
processors, only 'logical' ones. The worst case scenario here is where
Win2K is loading its logical processors 1 and 2 to the max, but in
reality this is only loading physical processor 1 = performance ouch.
Licensing issues abound too, particularly where an app (or OS) is based
on processor count.
>> http://www.microsoft.com/windows2000/docs/hyperthreading.doc
Explains some of the detail, and there's lots more you'll see in a
simple Google search, (there's talk in some fora about various Linux
problems as well with certain kernel levels). I personally haven't
benchmarked it, so can't comment on any performance particulars.
Rgds,
David McClelland
Tivoli Storage Manager Certified Consultant
Operations Backup and Recovery Projects
Shared Infrastructure Development
Reuters
85 Fleet Street
London EC4P 4AJ
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Jason Lee
Sent: 10 November 2004 18:50
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: CPU Utilization
Hi there,
yes, we've disabled HT in the BIOS. Other boxes see "4" CPUS.
Thanks
jason
On Nov 10, 2004, at 10:44 AM, Neil Schofield wrote:
> Jason
>
> I've got to start by saying I know nothing about Linux so take this
> with a pinch of salt but...
>
> The Generation 3 (& Generation 4?) DL380 has hyper-threading Intel
> processors, so each physical processor appears as two virtual
> processors.
> Your dual processor system should therefore appear as a 4-way to the
> operating system, unless you've disabled hyper-threading in the
> hardware.
>
> I don't know whether there's anything you have to do to enable support
> for hyper-threading in your version of Linux.
>
> Regards
> Neil Schofield
> Yorkshire Water Services Ltd.
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