CPU VP
Question: on a Sun Fire V890 with 4 UltraSPARC IV chips that the OS reports as 8 CPUs (dual-core/threaded), should NUMCPUVPS be 3 or 7? Consensus: count the 8 logical CPUs, so 7 is fine (leave one for other work, or use all if the box is dedicated to IDS). Several posters went further, reporting good results on Solaris with more CPU VPs than physical CPUs (e.g. 10 or 12 VPs on 4–6 CPU boxes), suggesting you experiment and watch idle time with onstat -g glo and sar, provided IDS is the only application on the machine.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hello, our customer has Sun Fire V890 with 4*UltraSparc IV. But this 4 processors looks for OS like 8 processors (for example mpstat). How many CPU VP can I use? 3 or 7? Thank you Radek Matyas
Radek You can use 7. Keith -> -----Original Message----- -> From: Matyá¹ Radek [mailto:Radek.Matyas@pvt.cz] -> Sent: Tuesday, May 02, 2006 8:31 AM -> To: ids@iiug.org -> Subject: CPU VP [6637] -> -> -> -> Hello, -> our customer has Sun Fire V890 with 4*UltraSparc IV. But -> this 4 processors -> looks for OS like 8 processors (for example mpstat). How -> many CPU VP can I -> use? 3 or 7? -> -> Thank you -> Radek Matyas -> -> -> ************************************************************* -> ****************** -> Forum Note: Use "Reply" to post a response in the -> discussion forum. -> ******************************************************************************** ** This message is sent in strict confidence for the addressee only. It may contain legally privileged information. The contents are not to be disclosed to anyone other than the addressee. Unauthorised recipients are requested to preserve this confidentiality and to advise the sender immediately of any error in transmission. This footnote also confirms that this email message has been swept for the presence of computer viruses, however we cannot guarantee that this message is free from such problems. ******************************************************************************** **
You can certainly use 7 unless you want to reserve some significant portion of the machine's CPU resources for other tasks. You may even want to experiment with using twice the number of CPU VPS as CPU Cores if this is a dedicated IDS server as the UltraSparc IV is fast enough to support 2 CPU VPs per core. Art S. Kagel ----- Original Message ----- From: Matyá¹¹ Radek <ids@iiug.org> At: 5/02 3:40:22 Hello, our customer has Sun Fire V890 with 4*UltraSparc IV. But this 4 processors looks for OS like 8 processors (for example mpstat). How many CPU VP can I use? 3 or 7? Thank you Radek Matyas ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.
I have heard that Sun is now going to dual-cpu processors. There are probably 8 real processors in the box. Bob Roussey -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Matyá¹ Radek Sent: Tuesday, May 02, 2006 3:31 AM To: ids@iiug.org Subject: CPU VP [6637] Hello, our customer has Sun Fire V890 with 4*UltraSparc IV. But this 4 processors looks for OS like 8 processors (for example mpstat). How many CPU VP can I use? 3 or 7? Thank you Radek Matyas ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.
Hi, You can use even more than 8. I have made some good experience setting the number to a value greater than the existing amount of CPUs (on another machine: 6 Proc x 400 MHz in a Sun 4500, NUMCPUVPS set to 10). Especially with Solaris, you might get a better performance if Informix thinks you have more real processors. If you see that the instance is heavily loaded, but the processors do not reach more than 60 % (in sar), it is worth experimenting with this value. All this only if Informix is the only application on the machine ;) Marcus -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Matyá¹ Radek Sent: Tuesday, May 02, 2006 9:31 AM To: ids@iiug.org Subject: CPU VP [6637] Hello, our customer has Sun Fire V890 with 4*UltraSparc IV. But this 4 processors looks for OS like 8 processors (for example mpstat). How many CPU VP can I use? 3 or 7? Thank you Radek Matyas **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum.
Hi,
my experience is the same as Marcus explained. As long as the engine has
more than 30% idle time, you should increase the number of CPU-VPs an
control using "onstat -g glo" if they are realy working. On Solaris i had very
good performance using 12 CPU-VPs on a box with only 4 CPUs.
gerd
>
> Hi,
>
> You can use even more than 8. I have made some good experience setting the
> number to a value greater than the existing
> amount of CPUs (on another machine: 6 Proc x 400 MHz in a Sun 4500,
> NUMCPUVPS set to 10). Especially with Solaris, you might get a better
> performance if Informix thinks you have more real processors.
> If you see that the instance is heavily loaded, but the processors do not
> reach more than 60 % (in sar), it is worth experimenting with this value.
> All this only if Informix is the only application on the machine ;)
>
> Marcus
>
> -----Original Message-----
> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Matyá¹
> Radek
> Sent: Tuesday, May 02, 2006 9:31 AM
> To: ids@iiug.org
> Subject: CPU VP [6637]
>
> Hello,
> our customer has Sun Fire V890 with 4*UltraSparc IV. But this 4 processors
> looks for OS like 8 processors (for example mpstat). How many CPU VP can I
> use? 3 or 7?
>
> Thank you
> Radek Matyas
>
> ****************************************************************************
> ***
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
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