IDS Forum

Re: IDS and P Series

Posted By: Paul Watson
Date: Saturday, 27 August 2011, at 9:56 a.m.

In Response To: Re: IDS and P Series (Art Kagel)

Test, test and then test again :-)

> You are absolutelyu right Paul. The Sun T-class or Niagra processors are
> brain-dead. They were specifically designed to run web servers and other
> Java or C++ style multi-threaded applications that run many many very
> short
> run threads that spend most of their time waiting for other threads to
> coordinate. To accomplish efficiently Sun had to eliminate the pre-fetch
> queues that made modern SMT processors so good at running databases and
> other long running threads/processes. With no pre-fetch queue Informix's
> style of multithreading just is not efficient. Indeed, Oracle has the same
> problem running on Niagra processors - DB2 does best but still does not
> run
> as well on the T-class processors as it does on the traditional SMT
> oriented
> M-class Sparc processors.
>
> While IBM built similar hardware threading into the P6 and P7 processors
> as
> that on the Niagra cores, they did not do away with the pre-fetch queues
> and
> so performance is comparable to or better than a non-threaded P5 processor
> core running at the same speed.
>
> Art
>
> Art S. Kagel
> Advanced DataTools (www.advancedatatools.com)
> Blog: http://informix-myview.blogspot.com/
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions
> and
> do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
> organization with which I am associated either explicitly, implicitly, or
> by
> inference. Neither do those opinions reflect those of other individuals
> affiliated with any entity with which I am affiliated nor those of the
> entities themselves.
>
> On Fri, Aug 26, 2011 at 5:34 PM, Paul Watson <paul@oninit.com> wrote:
>
>> I would add the rule of thumb doesn't appear to be valid with latest Sun
>> processors, when I tested last I saw the greatest transaction through
>> put
>> with a one to one relationship with cores and CPU VPs
>>
>> Cheers
>> Paul
>>
>> -----Original Message-----
>> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
>> Fernando Nunes
>> Sent: Friday, August 26, 2011 4:28 PM
>> To: ids@iiug.org
>> Subject: Re: IDS and P Series [24741]
>>
>> I would not ignore threads... but in the end it may not be different
>> from
>> your rule.
>> P7 can be configure in SMT-4 and SMT-2. And although not all internal
>> CPU
>> units are in pairs (or more) in each core many of them are.
>> What I blindly agree is that you cannot multiply the number of cores by
>> 4
>> in
>> SMT-4 configured systems. As you could/should not multiply by 2 in SMT-2
>> P6.
>>
>> If you create a graphic of scalability that shows performance vs
>> threads,
>> it
>> will not be a straight line... It will be a curve with quick growth
>> between
>> 1 and 2 threads, and after that the growth will slow down.
>>
>> Different workloads will influence this. For example Java != databases
>>
>> Regards
>>
>> On Fri, Aug 26, 2011 at 6:01 PM, Art Kagel <art.kagel@gmail.com> wrote:
>>
>> > I have experience with one client P7 system and a couple of P6
>> systems.
>> The
>> > P7s are an improvement over the P6. That said I would ignore the
>> hardware
>> > threading and just count cores for configuring Informix. The rule of
>> thumb
>> > stands, even on these machines, one CPU VP per 450-500 MHZ. A big hint
>> is
>> > that IBM licenses Informix by the number of cores, not threads!
>> >
>> > Art
>> > On Aug 26, 2011 12:07 PM, "Peter_Logan@spartanstores.com" <
>> > Peter_Logan@spartanstores.com> wrote:
>> > > Hello ...
>> > >
>> > > I have been asked by my management if IDS will take advantage of the
>> new
>> > P
>> >
>> > > Series chips that are multi threaded. From what I understand a
>> single
>> > > core will have 4 threads that run on it. They are calling it SMT.
>> I'm
>> > > going to guess that IDS would see each thread as a processor .. but
>> > wanted
>> >
>> > > to make sure.
>> > >
>> > > Thanks in advance for any info. I think these are the IBM P 7 series
>> > > chips ...
>> > >
>> > > Peter Logan
>> > > Senior Database Administrator
>> > > Phone: 616/878-8309
>> > >
>> > >
>> > >
>> >
>> >
>> >
>>
>> ****************************************************************************
>> ***
>> >
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>> > >
>> >
>> > --90e6ba212393f2226a04ab6b7e49
>> >
>> >
>> >
>> >
>>
>> ****************************************************************************
>> ***
>> > Forum Note: Use "Reply" to post a response in the discussion forum.
>> >
>> >
>>
>> --
>> Fernando Nunes
>> Portugal
>>
>> http://informix-technology.blogspot.com
>> My email works... but I don't check it frequently...
>>
>> --20cf3002555a9b816204ab6f374e
>>
>>
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>>
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>>
> *******************************************************************************
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>
> --90e6ba21241d1ebe7604ab70445e
>
>
> *******************************************************************************
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>

--
Paul Watson
Tel: +1 913-674-0360
Mob: +1 913-387-7529
Web: www.oninit.com

www.advancedatatools.com

Failure is not as frightening as regret.
If you want to improve, be content to be thought foolish and stupid.

Messages In This Thread

• IDS and P Series
  Peter_Logan@spartanstores.com -- Friday, 26 August 2011, at 12:06 p.m.
  • Re: IDS and P Series
    Art Kagel -- Friday, 26 August 2011, at 1:01 p.m.
    • Re: IDS and P Series
      Fernando Nunes -- Friday, 26 August 2011, at 5:27 p.m.
      • RE: IDS and P Series
        Paul Watson -- Friday, 26 August 2011, at 5:34 p.m.
        • Re: IDS and P Series
          Fernando Nunes -- Friday, 26 August 2011, at 6:36 p.m.
        • Re: IDS and P Series
          Art Kagel -- Friday, 26 August 2011, at 6:43 p.m.
          • Re: IDS and P Series
            Paul Watson -- Saturday, 27 August 2011, at 9:56 a.m.
  • Re: IDS and P Series
    Richard Kofler -- Saturday, 27 August 2011, at 5:49 a.m.

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