Why the platform focus?

Article: Tukwila Update
By: someone (someone.delete@this.somewhere.com), February 5, 2009 1:24 pm
Room: Moderated Discussions
Linus Torvalds (torvalds@linux-foundation.org) on 2/5/09 wrote:
>someone (someone@somewhere.com) on 2/5/09 wrote:
>>According to this study half of SPECint2006 programs have
>>average core working sets exceeding 16 MB and nearly 20%
>>exceed 32 MB:
>Oh, you need more memory than the caches have, but I really
>doubt that SpecInt has become that sensitive to the
>cache size. At some point the numbers were along the lines
>of "max 10% improvement from tripling the cache".
>So no, SpecInt2006 certainly won't fit in the cache,
>but with a larger cache you do capture a hell of a lot
>of it. Things have a lot of locality. From a cache size
>standpoint, the interesting part is the momentary working
>>The maximum cache one core/thread can use is 6 MB in C2D,
>>8 MB in i7, and 12 MB in Itanium.
>Actually, the number I quoted for Itanium was for the
>18MB L3 cache (does that make it 9M per core?). Why?

Half the L3 capacity is dedicated to each CPU.

>Because that's the highest performance result I found, due
>most likely to the 1.66GHz (rather than 1.6GHz) sku.
>That should already tell you something: it's not nearly
>as cache sensitive as it is frequency-sensitive. The
>smaller cache wins, just because it runs a tiny bit

No. HP only sells the 24 MB SKU in bigger machines with
slower memory systems and/or slower FSBs.

Same compiler, 1.6 GHz:

r6600, 24 MB L3, 533 MHz FSB - 14.5 SPECint_base2006
r3600, 18 MB L3, 533 MHz FSB - 13.9 "
r2620, 18 MB L3, 400 MHz FSB - 13.4 "

33% more BW = +4%
33% more L3 = +4%
33% more BW+L3 = +8%

Changes - Mont 9xxx -> Tukwila:

smaller L3 per core (12/9 MB -> 6 MB per core)
lower memory latency (4s: 10s of ns, 16s+: 100s of ns)
higher mem BW per core (0.8-2.6 GB/s -> 8.5 GB/s)
higher CPU frequency (1.60-1.66 -> 2 GHz = 20-25%)


- SPECint likely won't improve too much (<10% ?) above
GHz increase (20-25%) and compiler improvements (???).

- bigger improvements in SPECfp, huge improvements in

- bigger system = bigger relative performance boost.
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TopicPosted ByDate
Tukwila Update - article onlineDavid Kanter2009/02/04 11:03 PM
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            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
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                Tukwila Update - article onlineRagingDragon2009/02/07 02:51 PM
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                Tukwila Update - article onlinesomeone2009/02/06 08:19 AM
                Tukwila Update - article onlinesavantu2009/02/06 09:19 AM
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                    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
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      Tukwila Update - article onlineanon2009/02/05 09:16 PM
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        Tukwila Update - article onlinesomeone2009/02/06 06:32 AM
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    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
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                Intel puts its money where its mouth issomeone2009/02/08 01:24 PM
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                    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
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                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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