Question about installing/configuring SQL Server on hyperthreaded machine

We have a 4-proc machine we're considering enabled hyperthreading (so it
appears as 8-procs to the OS).
Question:
Does anyone have any experience using hyperthreading for a SQL Server
machine?
And if so, what information would you enter in "Per Processor" license
information during SETUP?
Would we enter 4, and SQL would know it has "8 logical CPUs" to work
with -- since that's what's visible to the OS?
Any insights or tips you might have would be appreciated. I'm having a hard
time find SQL-specific information on hyperthreading.
Thanks,
DanOKAY: I think I found my answer here:
http://www.microsoft.com/sql/howtobuy/hyperthreading.asp
Also: Good discussion here:
http://www.sqlmag.com/Forums/messageview.cfm?catid=5&threadid=17976
(Posting here for anyone else's benefit)
"Dan Carollo" <dan.carollo@.verizon.net> wrote in message
news:ucatQU1ZDHA.652@.TK2MSFTNGP10.phx.gbl...
> We have a 4-proc machine we're considering enabled hyperthreading (so it
> appears as 8-procs to the OS).
> Question:
> Does anyone have any experience using hyperthreading for a SQL Server
> machine?
> And if so, what information would you enter in "Per Processor" license
> information during SETUP?
> Would we enter 4, and SQL would know it has "8 logical CPUs" to work
> with -- since that's what's visible to the OS?
> Any insights or tips you might have would be appreciated. I'm having a
hard
> time find SQL-specific information on hyperthreading.
> Thanks,
> Dan
>
>|||I ran a benchmark with one of our applications uner Windows 2000 and
found a 15% performance increase with Hyperthreading enabled. Of
course, your actual performance may vary. If performance in important
in your environment, I suggest you experiment with HT enabled and
disabled to determine the best approach in your situation.
Licensing, is per *physical* processor.
--
Hope this helps.
Dan Guzman
SQL Server MVP
--
SQL FAQ links (courtesy Neil Pike):
http://www.ntfaq.com/Articles/Index.cfm?DepartmentID=800
http://www.sqlserverfaq.com
http://www.mssqlserver.com/faq
--
"Dan Carollo" <dan.carollo@.verizon.net> wrote in message
news:ucatQU1ZDHA.652@.TK2MSFTNGP10.phx.gbl...
> We have a 4-proc machine we're considering enabled hyperthreading (so
it
> appears as 8-procs to the OS).
> Question:
> Does anyone have any experience using hyperthreading for a SQL Server
> machine?
> And if so, what information would you enter in "Per Processor" license
> information during SETUP?
> Would we enter 4, and SQL would know it has "8 logical CPUs" to work
> with -- since that's what's visible to the OS?
> Any insights or tips you might have would be appreciated. I'm having
a hard
> time find SQL-specific information on hyperthreading.
> Thanks,
> Dan
>
>