Why the platform focus?

Article: Tukwila Update
By: Default (structuredmayhem.delete@this.hotmail.com), February 5, 2009 12:29 pm
Room: Moderated Discussions
>(And obviously things change if you have much less cache.
>The difference between 1MB and 2M is going to be quite big.
>But when everybody involved has 8M+ of cache, what matters
>most is how fast the cache is - at different levels -
>and the core itself. Not so much the platform outside the

I have to agree, the core architecture of EPIC has always been questionable.

First off, from what I've seen of the architecture, there doesn't seem to be a way to parallelize operations outside of those grouped in the 128-bit bundles. This is a serious deficiency when you compare the large IPC jumps seen with the P6 and Core2 - in the long-run, EPIC can't compete without a microarchitecture change. Sure, you can throw more cores at the problem, but more cores can only so so much for single-threaded problems.

The other problem is the use of branch predication to replace branch prediction + pipeline flush. Branch predication means you take every branch, and don't have to flush the pipeline on a bad branch. But the downside of predication is this: every branch taken means you have to load data from every single execution path, even those not taken. With no obvious pattern to the data, the cache tends to get fragmented more easily then other platforms, so it has to be huge.

I mean, you have to question this whole approach when the i7 tears a hole in the Itanium without even trying. How long is Intel's VLIW experiment going to last?
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Tukwila Update - article onlineDavid Kanter2009/02/04 11:03 PM
  Tukwila Update - article onlineDan2009/02/05 02:17 AM
    Tukwila Update - article onlineJoe Chang2009/02/05 08:16 AM
    Tukwila Update - article onlineTemp2009/02/05 08:25 AM
      Tukwila Update - article onlinePaul2009/02/05 11:29 AM
        Tukwila Update - article onlineDavid Kanter2009/02/05 05:32 PM
          Tukwila Update - article onlinePhil2009/02/06 12:24 AM
            Great. Finally hard numbersMichael S2009/02/06 03:46 AM
            Tukwila Update - article onlinelubemark2009/02/06 04:54 AM
              Tukwila Update - article onlinePhil2009/02/06 06:29 AM
                Tukwila Update - article onlineRagingDragon2009/02/07 02:39 PM
                  Tukwila Update - article onlineMichael S2009/02/07 03:09 PM
            Tukwila Update - article onlinesavantu2009/02/06 05:23 AM
              Tukwila Update - article onlineMichael S2009/02/06 06:13 AM
            Tukwila Update - article onlinesomeone2009/02/06 06:18 AM
              Tukwila Update - article onlinePhil2009/02/06 06:47 AM
                Tukwila Update - article onlinesomeone2009/02/06 07:17 AM
                Tukwila Update - article onlineRagingDragon2009/02/07 02:51 PM
              Tukwila Update - article onlineLinus Torvalds2009/02/06 07:37 AM
                Tukwila Update - article onlinesomeone2009/02/06 08:19 AM
                Tukwila Update - article onlinesavantu2009/02/06 09:19 AM
                  Tukwila Update - article onlineLinus Torvalds2009/02/06 09:40 AM
                    Tukwila Update - article onlinesavantu2009/02/06 10:00 AM
              Tukwila Update - article onlinePhil2009/02/09 03:54 AM
                Tukwila Update - article onlineDoug Siebert2009/02/09 09:40 PM
                  Tukwila Update - article onlineJouni Osmala2009/02/10 12:03 AM
                  Tukwila Update - article onlinesomeone2009/02/10 05:15 AM
                Tukwila Update - article onlineslacker2009/02/10 05:22 PM
    Tukwila Update - article onlineMichael S2009/02/05 02:56 PM
    Tukwila Update - article onlineDavid Kanter2009/02/05 03:55 PM
    Tukwila Update - article onlinesomeone2009/02/05 04:47 PM
      Tukwila Update - article onlineanon2009/02/05 09:16 PM
        Tukwila Update - article onlineRagingDragon2009/02/05 09:27 PM
        Tukwila Update - article onlinesomeone2009/02/06 06:32 AM
          Tukwila Update - article onlineanon2009/02/06 08:25 AM
            Tukwila Update - article onlinesomeone2009/02/06 08:40 AM
  POWER6 memory bandwidthMichael S2009/02/05 02:30 AM
    POWER6 memory bandwidthsomeone2009/02/05 06:00 AM
      POWER6 memory bandwidthMichael S2009/02/05 06:36 AM
      POWER6 interconnectconfused2009/02/05 09:50 AM
        POWER6 interconnectfoobar2009/02/05 01:12 PM
    POWER6 memory bandwidthWes Felter2009/02/05 11:57 AM
    POWER6 memory bandwidthJesper Frimann2009/02/09 10:54 PM
      POWER6 memory bandwidthMichael S2009/02/10 06:21 AM
  Why the platform focus?Linus Torvalds2009/02/05 07:40 AM
    Why the platform focus?savantu2009/02/05 07:50 AM
      Why the platform focus?Vincent Diepeveen2009/02/05 08:29 AM
        Why the platform focus?savantu2009/02/05 09:34 PM
          Why the platform focus?Vincent Diepeveen2009/02/05 10:09 PM
          Why the platform focus?Phil2009/02/06 12:10 AM
            Why the platform focus?savantu2009/02/06 12:50 AM
              Why the platform focus?Phil2009/02/06 06:09 AM
                Why the platform focus?savantu2009/02/06 09:08 AM
                Why the platform focus?someone2009/02/06 09:21 AM
                  Why the platform focus?mpx2009/02/06 01:04 PM
                    Why the platform focus?someone2009/02/06 01:16 PM
                Why the platform focus?RagingDragon2009/02/07 03:16 PM
                Why the platform focus?mas2009/02/25 07:28 AM
              itanium bigger than entire car industryVincent Diepeveen2009/02/06 06:12 AM
                itanium bigger than entire car industryDevon Welles2009/02/06 06:51 AM
                  itanium bigger than entire car industryVincent Diepeveen2009/02/06 09:41 AM
                  itanium bigger than entire car industryDean Kent2009/02/06 06:56 PM
                    Unit sales is meaningless when ASP grows fastersomeone2009/02/07 08:38 AM
                      Unit sales is meaningless when ASP grows fasterDean Kent2009/02/07 02:10 PM
                        Unit sales is meaningless when ASP grows fasterRagingDragon2009/02/07 03:34 PM
                    itanium bigger than entire car industryVincent Diepeveen2009/02/08 04:35 AM
                itanium bigger than entire car industryRagingDragon2009/02/07 03:40 PM
            Why the platform focus?Vincent Diepeveen2009/02/06 06:47 AM
      Yes it doesm performance mattersbob2009/02/05 09:51 AM
        Yes it doesm performance mattersVenki2009/02/05 10:06 AM
      Why the platform focus?Doug Siebert2009/02/06 12:07 AM
        Why the platform focus?savantu2009/02/06 01:00 AM
    Why the platform focus?someone2009/02/05 09:49 AM
      Why the platform focus?Linus Torvalds2009/02/05 11:03 AM
        Why the platform focus?Default2009/02/05 12:29 PM
          Why the platform focus?anon2009/02/05 01:08 PM
        Why the platform focus?someone2009/02/05 01:24 PM
          Why the platform focus?Linus Torvalds2009/02/05 02:30 PM
    Why the platform focus?Paradox2009/02/05 10:22 AM
    Why the platform focus?slacker2009/02/05 12:41 PM
      Why the platform focus?RagingDragon2009/02/05 09:57 PM
      Why the platform focus?Michael S2009/02/06 05:11 AM
        Why the platform focus?slacker2009/02/06 12:58 PM
          Why the platform focus?Michael S2009/02/08 01:24 AM
            Why the platform focus?someone2009/02/08 08:38 AM
              Why the platform focus?David Kanter2009/02/08 03:27 PM
                Why the platform focus?someone2009/02/08 06:26 PM
                  Why the platform focus?savantu2009/02/08 11:35 PM
          Why the platform focus?someone2009/02/08 08:53 AM
    All x86 SpecInt scores are useless due to autopar (NT)Michael S2009/02/05 02:15 PM
      Auto parallelizationDavid Kanter2009/02/05 05:17 PM
      All x86 SpecInt scores are useless due to autopar (NT)Paradox2009/02/06 07:47 AM
    Why the platform focus?David Kanter2009/02/05 03:49 PM
    Why the platform focus?David Kanter2009/02/06 12:09 AM
      Why the platform focus?Linus Torvalds2009/02/06 07:14 AM
        Why the platform focus?savantu2009/02/06 09:37 AM
          Why the platform focus?Linus Torvalds2009/02/06 11:49 AM
            Why the platform focus?Linus Torvalds2009/02/06 12:09 PM
            Intel puts its money where its mouth issomeone2009/02/06 01:08 PM
              Intel puts its money where its mouth isRagingDragon2009/02/07 05:01 PM
                Intel puts its money where its mouth issomeone2009/02/08 01:24 PM
                  mission-criticalMichael S2009/02/08 04:06 PM
                    mission-criticalmpx2009/02/09 01:30 AM
                      mission-criticalrwessel2009/02/09 02:23 PM
                    mission-criticalanon2009/02/09 02:55 AM
                    mission-criticalEduardoS2009/02/09 04:17 PM
                      mission-criticalDean Kent2009/02/09 07:11 PM
                        mission-criticalMichael S2009/02/10 04:20 AM
                          mission-criticalDean Kent2009/02/10 06:26 AM
                            mission-criticalMichael S2009/02/10 07:01 AM
                              mission-criticalDean Kent2009/02/10 12:36 PM
                            mission-criticalsomeone2009/02/10 08:05 AM
                              mission-criticalDean Kent2009/02/10 12:22 PM
                                mission-criticalZt2009/02/22 03:54 PM
                          mission-criticalanon2009/02/10 09:41 PM
                        mission-criticalEduardoS2009/02/10 12:46 PM
                          mission-criticalDean Kent2009/02/10 01:31 PM
                        mission-criticalslacker2009/02/10 06:30 PM
                    mission-criticalVincent Diepeveen2009/02/18 06:20 AM
                  Mission criticalmpx2009/02/09 12:00 AM
            Why the platform focus?savantu2009/02/07 12:15 AM
              Sun and x86 server differentiationDavid Kanter2009/02/07 12:34 AM
                Sun and x86 server differentiationmax2009/02/07 02:30 AM
                Sun and x86 server differentiationsomeone2009/02/07 09:19 AM
                  Sun and x86 server differentiationLinus Torvalds2009/02/07 09:44 AM
                Sun and x86 server differentiationRagingDragon2009/02/07 05:09 PM
                  Sun and x86 server differentiationMichael S2009/02/08 04:05 AM
                    Sun and x86 server differentiationRagingDragon2009/02/09 11:03 PM
                    Sun and x86 server differentiationJesper Frimann2009/02/09 11:51 PM
                      Sun and x86 server differentiationAlex Jones2009/02/10 12:43 PM
            Why the platform focus?bob2009/02/08 03:51 AM
              Why the platform focus?someone2009/02/08 08:23 AM
          missing the big pictureAM2009/02/18 05:43 AM
            missing the big pictureMichael S2009/02/18 07:42 AM
              missing the big pictureAM2009/02/18 08:03 AM
        Why the platform focus?mpx2009/02/06 11:47 AM
          Itanium - slowest and most obsolete server CPU family in the world, NOW.mpx2009/02/06 03:48 PM
            Itanium - slowest and most obsolete server CPU family in the world, NOW.Paul2009/02/07 01:56 PM
              z series?Michael S2009/02/07 02:12 PM
              Itanium - slowest and most obsolete server CPU family in the world, NOW.someone else2009/02/24 03:37 AM
                Itanium - slowest and most obsolete server CPU family in the world, NOW.EduardoS2009/02/24 05:55 AM
                  Itanium - slowest and most obsolete server CPU family in the world, NOW.someone else2009/02/25 12:55 AM
                    Itanium - slowest and most obsolete server CPU family in the world, NOW.Michael S2009/02/25 01:27 AM
          Why the platform focus?RagingDragon2009/02/07 05:18 PM
            Why the platform focus?Paul2009/02/08 12:10 PM
              Why the platform focus?Jukka Larja2009/02/08 10:04 PM
        Why the platform focus?slacker2009/02/06 01:10 PM
          Why the platform focus?Linus Torvalds2009/02/06 01:40 PM
            Why the platform focus?savantu2009/02/06 01:51 PM
            Why the platform focus?someone2009/02/06 01:58 PM
              Why the platform focus?Linus Torvalds2009/02/07 08:26 AM
                Why the platform focus?someone2009/02/07 09:10 AM
                  Why the platform focus?Linus Torvalds2009/02/07 09:40 AM
                    Why the platform focus?someone2009/02/07 11:24 AM
                      Why the platform focus?Doug Siebert2009/02/07 11:32 PM
                        Why the platform focus?max2009/02/08 03:57 AM
                          Why the platform focus?Michael S2009/02/08 04:20 AM
                        Why the platform focus?someone2009/02/08 08:15 AM
                          Why the platform focus?Doug Siebert2009/02/08 10:36 PM
                      Why the platform focus?hobold2009/02/09 04:49 AM
                Why the platform focus?anon2009/02/24 12:57 AM
                  Why the platform focus?Linus Torvalds2009/02/24 08:45 AM
                    Why the platform focus?savantu2009/02/24 11:30 AM
                      Why the platform focus?slacker2009/02/24 12:51 PM
                        Why the platform focus?savantu2009/02/24 11:04 PM
                          Why the platform focus?Michael S2009/02/25 01:34 AM
                          Why the platform focus?anon2009/02/25 09:17 AM
                      Why the platform focus?max2009/02/25 10:15 AM
                    Why the platform focus?someone2009/02/24 04:43 PM
                      Why the platform focus?Doug Siebert2009/02/24 07:26 PM
                        Why the platform focus?Howard Chu2009/02/25 02:07 AM
                          Why the platform focus?someone2009/02/25 05:48 AM
                        Why the platform focus?someone2009/02/25 05:41 AM
                          Why the platform focus?Linus Torvalds2009/02/25 08:17 AM
                            Why the platform focus?someone2009/02/25 08:55 AM
                              has anyone seen Tukwila silicon?anon2009/02/25 09:38 AM
                              Why the platform focus?Linus Torvalds2009/02/25 10:05 AM
                                Why the platform focus?slacker2009/02/25 12:11 PM
                                Why the platform focus?a reader2009/02/26 08:11 PM
                                  Why the platform focus?rcf2009/02/27 12:32 PM
                                    Why the platform focus?max2009/02/27 01:11 PM
                                      Why the platform focus?rcf2009/02/27 02:50 PM
                            Why the platform focus?Vincent Diepeveen2009/02/25 03:30 PM
                            $40M sale to $16M companybob2009/02/25 07:25 PM
                              $40M sale to $16M companyRichard Cownie2009/02/26 11:21 AM
                  Why the platform focus?anonymous2009/02/24 10:52 AM
                    Why the platform focus?savantu2009/02/24 11:20 AM
                      Why the platform focus?anonymous2009/02/24 02:31 PM
                        Why the platform focus?savantu2009/02/24 11:05 PM
                        Why the platform focus?someone else2009/02/25 12:04 AM
                          Why the platform focus?Michael S2009/02/25 12:42 AM
                            Put me down for $500 that Poulson doesn't arrive earlier than Q4/2011 (NT)slacker2009/02/25 11:39 AM
                        Why the platform focus?someone2009/02/25 05:54 AM
                          Why the platform focus?anonymous2009/02/25 08:46 AM
                            Why the platform focus?someone2009/02/25 09:22 AM
                            Why the platform focus?anon2009/02/25 10:01 AM
                              Why the platform focus?anonymous2009/02/25 10:54 AM
                  Why the platform focus?mpx2009/02/24 01:11 PM
                    Why the platform focus?anon2009/02/24 07:57 PM
                      Why the platform focus?Doug Siebert2009/02/24 09:04 PM
                        Why the platform focus?anon2009/02/24 09:46 PM
                          Why the platform focus?Doug Siebert2009/02/25 04:13 PM
                            Why the platform focus?anon2009/02/25 07:53 PM
                              Why the platform focus?bob2009/02/25 08:00 PM
                                Please try to keep up (NT)anon2009/02/25 08:49 PM
                              Why the platform focus?Doug Siebert2009/02/25 11:09 PM
                                Why the platform focus?anon2009/02/26 12:12 AM
                                Why the platform focus?Michael S2009/02/26 01:16 AM
                                  Why the platform focus?James2009/02/26 05:09 AM
                                    sufficiently intimate with the OSMichael S2009/02/26 05:29 AM
                                      sufficiently intimate with the OSanon2009/02/27 12:01 AM
                                      sufficiently intimate with the OSHoward Chu2009/02/27 12:37 AM
                      Why the platform focus?Michael S2009/02/25 01:02 AM
                        Why the platform focus?anon2009/02/25 02:07 AM
              Why the platform focus?anon2009/02/07 12:18 PM
                Why the platform focus?Vincent Diepeveen2009/02/08 09:16 AM
                Why the platform focus?anon2009/02/25 06:40 AM
                  Intels financial statusVincent Diepeveen2009/02/25 11:02 AM
                Why the platform focus?someone2009/02/25 06:54 AM
      Why the platform focus?Vincent Diepeveen2009/02/06 07:20 AM
        Why the platform focus?Default2009/02/06 08:57 AM
          Why the platform focus?Vincent Diepeveen2009/02/06 09:59 AM
          Why the platform focus?RagingDragon2009/02/07 05:43 PM
  Tukwila Update - article onlineVincent Diepeveen2009/02/05 08:11 AM
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