Re: Very good news from AMD

Message-ID	<4E19FC3A.6090003@SPAM.comp-arch.net> (permalink)
Date	2011-07-10 12:23 -0700
From	"Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net>
Organization	comp-arch.net
Newsgroups	comp.arch
Subject	Re: Very good news from AMD
References	(1 earlier) <8762ncevv6.fsf@NaN.sparse.dyndns.org> <4E179E0B.1010902@SPAM.comp-arch.net> <87oc13rolb.fsf@NaN.sparse.dyndns.org> <4E194AAF.6030307@SPAM.comp-arch.net> <87sjqeqbss.fsf@NaN.sparse.dyndns.org>

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On 7/10/2011 10:34 AM, Jason Riedy wrote:
> And Andy Glew writes:
>> Memory may be failing me, but I think that the MTA was a fixed
>> barrel scheduled machine.  Did thy not have a fixed 128 threads
>> per node, and always switch from thread to thread, every cycle,
>> with no variation in the schedule?
>
> It switched to the next *ready* stream.  If a stream is waiting
> for memory, it isn't ready and is skipped by scheduling.
> Similarly, if a stream already has an instruction in the pipe,
> it's skipped.
>
> My old micro-benchmarks made the scheduling look a bit more
> dynamic than a simple barrel even without memory interaction.
> There was a large variation in the number of cycles between
> consecutive instructions in a single stream.


OK, that is pretty much what the GPUs do.  With the addition that they 
operate on SIMT.  AMD's next geberation may be getting rid of the 
coherent threading, and be a more classsic vector archittecture, 
although picking a 10 instructions, each from 1 thread out of 40, per cycle.

Thread

Very good news from AMD Quadibloc <jsavard@ecn.ab.ca> - 2011-07-07 20:14 -0700
  Re: Very good news from AMD Jason Riedy <jason@lovesgoodfood.com> - 2011-07-08 09:37 -0400
    Re: Very good news from AMD "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-07-08 09:33 -0700
      Re: Very good news from AMD "Paul A. Clayton" <paaronclayton@gmail.com> - 2011-07-08 16:21 -0700
        Re: Very good news from AMD "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-07-08 17:30 -0700
          Re: Very good news from AMD "Paul A. Clayton" <paaronclayton@gmail.com> - 2011-07-25 20:24 -0700
    Re: Very good news from AMD Robert Myers <rbmyersusa@gmail.com> - 2011-07-08 12:33 -0700
      Re: Very good news from AMD Thomas Womack <twomack@chiark.greenend.org.uk> - 2011-07-08 20:59 +0100
        Re: Very good news from AMD Robert Myers <rbmyersusa@gmail.com> - 2011-07-09 14:57 -0700
    Re: Very good news from AMD "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-07-08 17:17 -0700
      Re: Very good news from AMD Jason Riedy <jason@lovesgoodfood.com> - 2011-07-09 20:01 -0400
        Re: Very good news from AMD "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-07-09 23:46 -0700
          Re: Very good news from AMD Jason Riedy <jason@lovesgoodfood.com> - 2011-07-10 13:34 -0400
            Re: Very good news from AMD "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-07-10 12:23 -0700
    Re: Very good news from AMD Quadibloc <jsavard@ecn.ab.ca> - 2011-07-08 18:14 -0700
    Re: Very good news from AMD Quadibloc <jsavard@ecn.ab.ca> - 2011-07-09 10:19 -0700
  Re: Very good news from AMD Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-07-08 23:11 +0200
  Re: Very good news from AMD "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-07-10 09:39 +0200
    Re: Very good news from AMD "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-07-11 10:37 +0200
      Re: Very good news from AMD "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-07-12 03:55 +0200
        Re: Very good news from AMD "Skybuck Flying" <Windows7IsOK@DreamPC2006.com> - 2011-07-12 04:05 +0200

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