Independent micro threads

By: David Hess (davidwhess.delete@this.gmail.com), January 1, 2019 11:41 am
Room: Moderated Discussions
Doug S (foo.delete@this.bar.bar) on December 31, 2018 11:40 pm wrote:
>
> OK, but think about the possible sources of these hot spots. Where is the most activity on a modern
> CPU in the average case - probably the register file and ALUs (there are other places that might
> be like branch unit, ROB and so forth but the register file and ALUs will ALWAYS be hot)
>
> Those are essentially pinpoint sources in a modern CPU core - far less than 1 sq mm. If you spread out the transistors
> to take (just as an example) a 0.25 sq mm area to 2.5 sq mm you now have longer wires. How much power does that
> waste? Does it affect your cycle time, since registers are now "further away" from the ALUs? If it does, you
> may lose the chance for the higher clock rates you were hoping to attain by spreading things out.

It is a definite trade off. Total power goes up but if power density is decreased, then it may allow higher total performance. For power density limited designs, wire delay already does not limit performance because if it did, then power density would not.

I thought at some point operating systems might move processing threads between cores "resting" most of the cores so they can cool off in order to maintain the highest possible clock speed but I suspect having to reload cache makes this into a loss for performance.

< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Independent micro threadsBrett2018/12/30 01:55 PM
  Independent micro threadsTravis Downs2018/12/30 04:18 PM
    Independent micro threadsBrett2018/12/30 07:16 PM
      Independent micro threadsTravis Downs2018/12/30 07:34 PM
        Independent micro threadsBrett2018/12/30 07:48 PM
          Independent micro threadsTravis Downs2018/12/30 09:06 PM
            Independent micro threadsBrett2018/12/30 10:57 PM
              Independent micro threadsTravis Downs2018/12/31 12:42 AM
                Independent micro threadsBrett2019/01/01 07:02 PM
                  Independent micro threadsMichael S2019/01/02 02:01 AM
                    Independent micro threadsMaynard Handley2019/01/02 03:29 PM
              Independent micro threadsMontaray Jack2019/01/01 02:12 AM
  Independent micro threadsanon2018/12/30 04:34 PM
  Independent micro threadsPaul A. Clayton2018/12/30 05:15 PM
  Independent micro threadsDavid Hess2018/12/30 06:47 PM
    Independent micro threadsDomaldel2018/12/30 07:06 PM
      Independent micro threadsDavid Hess2018/12/30 07:26 PM
        Independent micro threadsDoug S2018/12/31 10:26 AM
          Independent micro threadsDavid Hess2018/12/31 09:32 PM
            Independent micro threadsDoug S2019/01/01 12:40 AM
              Independent micro threadsDavid Hess2019/01/01 11:41 AM
            Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Domaldel2019/01/01 12:40 AM
              Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Domaldel2019/01/01 12:44 AM
                Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Domaldel2019/01/01 12:49 AM
                  Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Domaldel2019/01/01 12:51 AM
              Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Simon Farnsworth2019/01/01 06:05 AM
                Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Domaldel2019/01/01 08:01 AM
                Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")Maynard Handley2019/01/01 01:17 PM
                  Taking things to extremes.Domaldel2019/01/01 05:44 PM
                    Yes, I know, the forum is named *Real* World Tech, but I'm thinking that perhapsDomaldel2019/01/01 05:52 PM
                      Yes, I know, the forum is named *Real* World Tech, but I'm thinking that perhapsMontaray Jack2019/01/02 07:26 AM
                        Yes, I know, the forum is named *Real* World Tech, but I'm thinking that perhapsMontaray Jack2019/01/02 08:21 AM
                    Taking things to extremes.Maynard Handley2019/01/01 06:55 PM
                    Taking things to extremes.Kevin G2019/01/04 08:57 AM
              Overcomming thermal limits of a high dencity 3D arcitecture (Formerly "Independent micro threads")David Hess2019/01/01 11:36 AM
    Independent micro threadsTravis Downs2018/12/30 07:38 PM
    Independent micro threadsBrett2018/12/30 07:41 PM
  Independent micro threadsanon2018/12/30 08:20 PM
    Independent micro threadsBrett2018/12/30 08:51 PM
      Independent micro threadsTravis Downs2018/12/30 09:48 PM
        Mill and Independent micro threadsBrett2019/01/01 07:39 PM
          No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Heikki Kultala2019/01/02 12:29 AM
            No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Brett2019/01/02 01:15 AM
              No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Heikki Kultala2019/01/02 02:22 AM
                No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Brett2019/01/03 01:13 AM
                  "Leaf branch" is not a commonly used termHeikki Kultala2019/01/03 03:48 AM
                    "Leaf branch" is not a commonly used termBrett2019/01/03 04:35 AM
                      You lack parallelism than OoOE givesHeikki Kultala2019/01/03 07:38 AM
                        You lack parallelism than OoOE givesBrett2019/01/04 02:41 AM
                          You lack parallelism than OoOE givesBrett2019/01/04 04:10 PM
                            You lack parallelism than OoOE givesBrett2019/01/05 08:29 PM
                              Mill speculates, more parallelism than OoOE givesBrett2019/01/05 08:31 PM
                                Mill *is* a speculationEric Bron2019/01/06 05:04 AM
                                  Mill *is* a speculationMichael S2019/01/06 05:53 AM
                                    Mill *is* a speculationBrett2019/01/06 09:03 PM
                                  Mill *is* a speculationjuanrga2019/01/06 06:10 AM
                                    probably ~2 (NT)Michael S2019/01/06 06:51 AM
                                  Mill *is* a speculationBrett2019/01/06 01:18 PM
                                    Mill *is* a speculationEric Bron2019/01/06 03:36 PM
                                      Mill *is* a speculationBrett2019/01/06 08:47 PM
                                        Mill *is* a speculationJacob Marley2019/01/06 10:29 PM
                                          Mill *is* a speculationBrett2019/01/07 04:24 AM
                                            Mill *is* a speculationMichael S2019/01/07 05:23 AM
                                            Mill *is* a speculationEric Bron2019/01/07 05:36 AM
                                              Mill *is* a speculationBrett2019/01/07 03:40 PM
                                                Mill *is* a speculationEric Bron2019/01/07 05:32 PM
                                            Mill is something you don't understandHeikki Kultala2019/01/08 04:19 AM
                                              Mill is something you don't understandMichael S2019/01/08 07:44 AM
                                                Itanium and static vs dynamicHeikki Kultala2019/01/09 03:14 AM
                                                  Itanium and static vs dynamicPaul A. Clayton2019/01/09 08:51 AM
                                        Mill *is* a speculationEric Bron2019/01/07 05:27 AM
                                          Mill *is* a speculationEric Bron2019/01/07 06:23 AM
                                      Mill *is* a speculationanon2019/01/07 06:24 AM
                                        Mill *is* a speculationEric Bron2019/01/07 06:52 AM
                                          Mill *is* a speculationanon2019/01/07 08:36 AM
                                            Mill *is* a speculationEric Bron2019/01/07 09:20 AM
                                        Mill *is* a speculationjuanrga2019/01/07 10:22 AM
                                          Mill *is* a speculationanon2019/01/07 01:16 PM
                                        Mill *is* a speculationanon2019/01/07 09:46 PM
                                          Mill *is* a speculationanon2019/01/08 01:56 AM
                                            Mill *is* a speculationanon2019/01/08 03:39 AM
                                              Mill *is* a speculationMichael S2019/01/08 03:52 AM
                                                Mill *is* a speculationanon2019/01/08 10:10 PM
                                                  Wasted width not wasted work.Brett2019/01/09 11:44 AM
                                                    No such thing was declared. (NT)anon2019/01/09 03:41 PM
                                                    Very simple test for new uarch ideassomeone2019/01/10 07:03 AM
                                                      Very simple test for new uarch ideasdmcq2019/01/10 07:21 AM
                                                        Very simple test for new uarch ideasDoug S2019/01/10 10:01 AM
                                                          Very simple test for new uarch ideasDan Fay2019/01/10 01:13 PM
                                                      Very simple test for new uarch ideasanonymous22019/01/10 11:03 AM
                                                        Very simple test for new uarch ideasAlberto2019/01/10 11:32 AM
                                                      Very simple test for new uarch ideasEtienne2019/01/11 03:03 AM
                                                        Very simple test for new uarch ideasFoo_2019/01/11 04:31 AM
                                                          Very simple test for new uarch ideasEtienne2019/01/11 05:51 AM
                                                            Very simple test for new uarch ideasFoo_2019/01/11 05:53 AM
                                                              Very simple test for new uarch ideasdmcq2019/01/11 06:08 AM
                                                              Very simple test for new uarch ideasEtienne2019/01/11 06:13 AM
                                                                Very simple test for new uarch ideasFoo_2019/01/11 06:54 AM
                                                                  Very simple test for new uarch ideasEtienne2019/01/11 07:32 AM
                                                                    Very simple test for new uarch ideasBrett2019/01/11 10:25 AM
                                                                      Very simple test for new uarch ideasMegol2019/01/12 06:29 AM
                                                                        Very simple test for new uarch ideasMichael S2019/01/12 09:21 AM
                                                                          Word salad AI fundamentaliy brokenBrett2019/01/12 01:59 PM
                                                                          Very simple test for new uarch ideasMegol2019/01/13 11:51 AM
                                              Mill *is* a speculationanon2019/01/08 08:50 AM
                                                Mill *is* a speculationEric Bron2019/01/08 09:03 AM
                                                  Mill *is* a speculationanon2019/01/08 09:21 AM
                      "Leaf branch" is not a commonly used termMichael S2019/01/03 07:57 AM
                        "Leaf branch" is not a commonly used termBrett2019/01/04 03:29 AM
                  Calls are not needed for speculation for mill if there are no side effect,and dont help if there areHeikki Kultala2019/01/08 04:28 AM
              No. Mill does not get the hit because it does not get the benefit even when correctly predicted.anon2019/01/02 03:05 AM
              No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Doug S2019/01/02 11:38 AM
                No. Mill does not get the hit because it does not get the benefit even when correctly predicted.rwessel2019/01/02 05:53 PM
                  No. Mill does not get the hit because it does not get the benefit even when correctly predicted.anon2019/01/02 08:56 PM
                    itanicBrett2019/01/03 12:41 AM
                      itanicanon2019/01/03 03:12 AM
                      itanicDavid Hess2019/01/03 08:06 AM
                    No. Mill does not get the hit because it does not get the benefit even when correctly predicted.rwessel2019/01/03 09:18 AM
                      No. Mill does not get the hit because it does not get the benefit even when correctly predicted.anon2019/01/04 05:25 AM
                    Itanium could have been RISC or CISC - same outcomesomeone2019/01/04 07:45 AM
                      Itanium could have been RISC or CISC - same outcomeDoug S2019/01/04 12:39 PM
                        Itanium could have been RISC or CISC - same outcomeJan Olšan2019/01/04 01:58 PM
                          "fluffyRISC" has a namevvid2019/01/04 03:48 PM
                        Itanium could have been RISC or CISC - same outcomeBrett2019/01/04 03:43 PM
                      Itanium could have been RISC or CISC - same outcomeanonymou52019/01/04 12:41 PM
                  No. Mill does not get the hit because it does not get the benefit even when correctly predicted.David Hess2019/01/03 08:15 AM
                No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Maynard Handley2019/01/03 12:24 PM
                  No. Mill does not get the hit because it does not get the benefit even when correctly predicted.Maynard Handley2019/01/03 12:27 PM
                    No. Mill does not get the hit because it does not get the benefit even when correctly predicted.dmcq2019/01/04 01:59 AM
                  EPIC target marketsFoo_2019/01/04 06:29 AM
                    EPIC target marketsDoug S2019/01/04 12:42 PM
                      Lack of future visionDoug S2019/01/04 12:57 PM
                        Lack of future visionBrett2019/01/04 02:59 PM
                          Lack of future visionDoug S2019/01/04 04:25 PM
                            Lack of future visionBrett2019/01/04 05:18 PM
                              Lack of future visionDoug S2019/01/05 12:47 AM
                                Lack of future visionBrett2019/01/05 02:06 PM
                                  Lack of future visiondmcq2019/01/05 02:22 PM
                                  Lack of future visionanon2019/01/05 03:01 PM
                                    Lack of future visionMichael S2019/01/05 04:18 PM
                                      Lack of future visionanon2019/01/05 06:14 PM
                                        Lack of future visionMichael S2019/01/06 02:01 AM
                                          Lack of future visionanon2019/01/06 03:23 AM
                                          Mitch Alsup's MY66000 uses IF-like predication (I think) (NT)Paul A. Clayton2019/01/06 04:54 PM
                                            ??? (NT)Michael S2019/01/07 05:25 AM
                                            88K ? (NT)anonymous22019/01/07 04:20 PM
                                          Modestly expanded response: MY66000 predicate shadowPaul A. Clayton2019/01/07 11:53 AM
                      Thanks for the correction (NT)Foo_2019/01/04 04:31 PM
              No. Mill does not get the hit because it does not get the benefit even when correctly predicted.sdrc2019/01/04 07:36 AM
          Mill and Independent micro threadsMichael S2019/01/02 02:32 AM
Reply to this Topic
Name:
Email:
Topic:
Body: No Text
How do you spell green?