Re: [ActiveDir] DCs Hyper-Threading
I've always viewed HT as that in-between technology while dual core chips were being developed for the x86 platform and until 64b could come of age. The thinking generally was always back and forth between use it and disable it for various Microsoft server applications. It was discouraged for W2K by intel, but encourarged by some at Microsoft. Supposed to have been much improved in W2K3 (it shows properly now in taskmgr if that helps :) Confusing to say the least. I've used it without issue. I haven't really noticed a boost in perfromance either though. My thoughts: When it doubt, disable it. The goal here is the reliability and stability of the application (Active Directory in this case)and if performance is a problem you have other options such as 64b and dual-core solutions. IIRC,HT is still discouraged if using Virtual Server but double check if you plan to use it that way. Something in the readme as I recall that gives more information. Al On 8/7/06, Wyatt, David [EMAIL PROTECTED] wrote: What are people's views on whether to enable or disable hyper-threading on a Proliant box running Windows 2003 as a DC. I remember Intel advised HT to be disabled on Windows 2000 but has this changed for Windows 2003?. Are the performance benefits significant for a DC? Thanks David This message contains confidential information and is intended only for the individual or entity named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as an invitation or offer to buy or sell any securities or related financial instruments. GAM operates in many jurisdictions and is regulated or licensed in those jurisdictions as required.
Re: [ActiveDir] DCs Hyper-Threading
From Tim Mangan's whitepaper on hyperthreading under 2003: The results in this paper are exclusively related to Windows Server 2003. We are currently running the tests used in the development of this paper under erver 2000. We can verify reports of performance and stability problems with Hyper-Threading on Windows 2000 Server, and at this time recommend customers disable Hyper-Threading under 2000. http://www.tmurgent.com/images/WP_HyperThread.pdf So disable under 2000 is the recomendation, As to 2003 he shows a small performance increase in all cases except multithreaded CPU-bound applications, which is expected. Personally I leave hyperthreading turned on for my 2003 installs. It also makes single-dual cpu upgrades easier since the SMP kernal is already used =) Thanks, Andrew Fidel Wyatt, David [EMAIL PROTECTED] Sent by: [EMAIL PROTECTED] 08/07/2006 09:45 AM Please respond to ActiveDir@mail.activedir.org To ActiveDir@mail.activedir.org cc Subject [ActiveDir] DCs Hyper-Threading What are people's views on whether to enable or disable hyper-threading on a Proliant box running Windows 2003 as a DC. I remember Intel advised HT to be disabled on Windows 2000 but has this changed for Windows 2003?. Are the performance benefits significant for a DC? Thanks David This message contains confidential information and is intended only for the individual or entity named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as an invitation or offer to buy or sell any securities or related financial instruments. GAM operates in many jurisdictions and is regulated or licensed in those jurisdictions as required.
Re: [ActiveDir] DCs Hyper-Threading
I believe, from a past conversation, that
disabling hyper-threading on bridgehead servers with lots of inbound
connections, i.e. in enterprise deployments, should be *considered* as
the replication queue has two parallel threads for processor, core or hyper
threading processor as the system call sees all in the same way -multiple
processors. However, there's no real guideline here as there are so many
variables, i.e. amount of change, compression, new objects, mods, whether the
data is in cache or not, etc.
I don't think it matters all that much for
the AD stuff. You might need to look into the FRS side of things (in big
environments). It will matter for CPU-intensive apps that weren't written
directly for multiple-processor systems. Under such circumstances, it is
often recommended to disable hyper threading.
For example, you have to disable HT for
SAP servers. I don't think SQL cares as that is written for multiple-CPU
support and can probably tell the difference between two physical processors and
HT processors but don't know. Like Al said, check the Virtual Server
readme, as NIC teaming isn't supported for the host, apparently (unless, like
AD, that's just load-balanced teaming).
--Paul
- Original Message -
From:
[EMAIL PROTECTED]
To: ActiveDir@mail.activedir.org
Sent: Tuesday, August 08, 2006 2:11
PM
Subject: Re: [ActiveDir] DCs
Hyper-Threading
From Tim
Mangan's whitepaper on hyperthreading under 2003: "The results in this paper are exclusively related to
Windows Server 2003. We are currently running the tests used in the
development of this paper under erver 2000. We can verify reports of performance and stability problems with
Hyper-Threading on Windows 2000 Server, and at this time recommend customers
disable Hyper-Threading under 2000." http://www.tmurgent.com/images/WP_HyperThread.pdf So disable under 2000 is the recomendation, As to 2003
he shows a small performance increase in all cases except multithreaded
CPU-bound applications, which is expected. Personally I leave hyperthreading
turned on for my 2003 installs. It also makes single-dual cpu upgrades
easier since the SMP kernal is already used =) Thanks, Andrew
Fidel
"Wyatt, David"
[EMAIL PROTECTED] Sent
by: [EMAIL PROTECTED]
08/07/2006 09:45 AM
Please respond
toActiveDir@mail.activedir.org
To
ActiveDir@mail.activedir.org
cc
Subject
[ActiveDir] DCs
Hyper-Threading
What are people's views on whether to enable or disable hyper-threading
on a Proliant box running Windows 2003 as a DC. I remember Intel advised
HT to be disabled on Windows 2000 but has this changed for Windows 2003?.
Are the performance benefits significant for a DC? Thanks David This message contains confidential
information and is intended only for the
individual or entity named. If you are not the named addressee you should not disseminate,
distribute or copy this e-mail. Please
notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your
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late or incomplete, or contain viruses. The
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[ActiveDir] DCs Hyper-Threading
Title: Message What are people's views on whether to enable or disable hyper-threading on a Proliant box running Windows 2003 as a DC. I remember Intel advised HT to be disabled on Windows 2000 but has this changed for Windows 2003?. Are the performance benefits significant for a DC? Thanks David This message contains confidential information and is intended only for the individual or entity named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as an invitation or offer to buy or sell any securities or related financial instruments. GAM operates in many jurisdictions and is regulated or licensed in those jurisdictions as required.
