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From: Roman Shaposhnik <roman@shaposhnik.org>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] Barrelfish
Date: Sat, 17 Oct 2009 05:42:10 -0700	[thread overview]
Message-ID: <e763acc10910170542j29f48ba6g2876d62cade8fa7@mail.gmail.com> (raw)
In-Reply-To: <20091016170316.GA3135@nipl.net>

On Fri, Oct 16, 2009 at 10:03 AM, Sam Watkins <sam@nipl.net> wrote:
> On Thu, Oct 15, 2009 at 12:50:48PM +0100, Richard Miller wrote:
>> > It's easy to write good code that will take advantage of arbitrarily many
>> > processors to run faster / smoother, if you have a proper language for the
>> > task.
>>
>> ... and if you can find a way around Amdahl's law (qv).
>
> "The speedup of a program using multiple processors in parallel computing is
> limited by the time needed for the sequential fraction of the program."
>
> So it would only be a problem supposing that a significant part of the program
> is unparallelizable.  I can think of many many tasks where "Amdahl's law" is
> not going to be a problem at all, for a properly designed system.

Lets do a little math, shall we? Better yet, lets graph it:
   http://en.wikipedia.org/wiki/File:AmdahlsLaw.svg

Now, do you see what's on the right side of X axis? That's
right 65536 cores. Pause and appreciate the measeleness
of speedup...

Thanks,
Roman.



  parent reply	other threads:[~2009-10-17 12:42 UTC|newest]

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-14 19:09 Tim Newsham
2009-10-14 19:54 ` Roman Shaposhnik
2009-10-14 21:21   ` Tim Newsham
2009-10-14 21:33     ` Lyndon Nerenberg (VE6BBM/VE7TFX)
2009-10-14 21:42       ` Noah Evans
2009-10-14 21:45         ` erik quanstrom
2009-10-14 21:57           ` Noah Evans
2009-10-14 22:10         ` Eric Van Hensbergen
2009-10-14 22:21           ` Noah Evans
2009-10-15  1:03     ` David Leimbach
2009-10-15  1:50     ` Roman Shaposhnik
2009-10-15  2:12       ` Eric Van Hensbergen
2009-10-15 10:53       ` Sam Watkins
2009-10-15 11:50         ` Richard Miller
2009-10-15 12:00           ` W B Hacker
2009-10-16 17:03           ` Sam Watkins
2009-10-16 18:17             ` ron minnich
2009-10-16 18:39               ` Wes Kussmaul
2009-10-17 12:42             ` Roman Shaposhnik [this message]
2009-10-15 11:56         ` Josh Wood
2009-10-15 13:11         ` hiro
2009-10-15 15:05           ` David Leimbach
2009-10-18  1:15         ` Roman Shaposhnik
2009-10-18  3:15           ` Bakul Shah
     [not found]             ` <e763acc10910180606q1312ff7cw9a465d6af39c0fbe@mail.gmail.com>
2009-10-18 13:22               ` Roman Shaposhnik
2009-10-18 19:18                 ` Bakul Shah
2009-10-18 20:12                   ` ron minnich
2009-10-20  0:04                     ` [9fans] Parallelism is over a barrel(fish)? Lyndon Nerenberg (VE6BBM/VE7TFX)
2009-10-20  1:11                       ` W B Hacker
2009-10-14 21:36   ` [9fans] Barrelfish Eric Van Hensbergen
2009-10-15  2:05     ` Roman Shaposhnik
2009-10-15  2:17       ` Eric Van Hensbergen
2009-10-15  3:32         ` Tim Newsham
2009-10-15  3:59           ` Eric Van Hensbergen
2009-10-15 17:39             ` Tim Newsham
2009-10-15 18:28 ` Christopher Nielsen
2009-10-15 18:55   ` W B Hacker
     [not found] <<20091015105328.GA18947@nipl.net>
2009-10-15 13:27 ` erik quanstrom
2009-10-15 13:40   ` Richard Miller
2009-10-16 17:20   ` Sam Watkins
2009-10-16 18:18     ` Latchesar Ionkov
2009-10-19 15:26       ` Sam Watkins
2009-10-19 15:33         ` andrey mirtchovski
2009-10-19 15:50         ` ron minnich
2009-10-16 21:17     ` Jason Catena
2009-10-17 20:58       ` Dave Eckhardt
2009-10-18  2:09         ` Jason Catena
2009-10-18 16:02           ` Dave Eckhardt
2009-10-17 18:45   ` Eris Discordia
2009-10-17 21:07     ` Steve Simon
2009-10-17 21:18       ` Eric Van Hensbergen
2009-10-18  8:48         ` Eris Discordia
2009-10-18  8:44       ` Eris Discordia
2009-10-19 15:57     ` Sam Watkins
2009-10-19 16:03       ` ron minnich
2009-10-19 16:46       ` Russ Cox
2009-10-20  2:16       ` matt
2009-10-20  9:15         ` Steve Simon
2009-10-21 15:43         ` Sam Watkins
2009-10-21 16:11           ` Russ Cox
2009-10-21 16:37             ` Sam Watkins
2009-10-21 18:01           ` ron minnich
2009-10-28 15:37           ` matt
     [not found]   ` <A90043D02D52B2CBF2804FA4@192.168.1.2>
2009-10-18  0:06     ` ron minnich
2009-10-18  0:54       ` Roman Shaposhnik
     [not found] <<207092dc429fe476c2046d537aeaa400@hamnavoe.com>
2009-10-15 13:52 ` erik quanstrom
2009-10-15 15:07   ` David Leimbach
2009-10-15 15:21     ` roger peppe
2009-10-16 17:21       ` Sam Watkins
2009-10-16 23:39         ` Nick LaForge
2009-10-18  1:12         ` Roman Shaposhnik
2009-10-19 14:14           ` matt
2009-10-19 16:00           ` Sam Watkins
     [not found] <<4AD70EE9.1010208@conducive.org>
2009-10-15 13:52 ` erik quanstrom
     [not found] <<3e1162e60910150805q2ea3f682w688299a39274051c@mail.gmail.com>
2009-10-15 15:28 ` erik quanstrom
     [not found] <<20091016172030.GB3135@nipl.net>
2009-10-16 18:34 ` erik quanstrom
     [not found] <<d50d7d460910161417w45b5c675p8740315aaf6861f@mail.gmail.com>
2009-10-16 22:25 ` erik quanstrom
     [not found] <<20091018031508.717CE5B30@mail.bitblocks.com>
2009-10-19 13:44 ` erik quanstrom
2009-10-19 14:36   ` David Leimbach
     [not found] <<20091019155738.GB13857@nipl.net>
2009-10-19 16:05 ` erik quanstrom
2009-10-19 16:34   ` Sam Watkins
2009-10-19 17:30     ` ron minnich
2009-10-19 17:57       ` W B Hacker
2009-10-19 18:14       ` David Leimbach
     [not found] <<4ADC7439.3060502@maht0x0r.net>
2009-10-19 16:13 ` erik quanstrom
2009-10-19 18:23   ` tlaronde
2009-10-20  1:38   ` matt
2009-10-20  1:58     ` Eris Discordia
2009-10-20  2:17       ` matt
     [not found] <<20091019182352.GA1688@polynum.com>
2009-10-19 18:48 ` erik quanstrom
     [not found] <<4ADD147A.4090801@maht0x0r.net>
2009-10-20  2:11 ` erik quanstrom
2009-10-20  2:33   ` matt

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