Knights Landing CPU Speculation

Article: Knights Landing CPU Speculation
By: Patrick Chase (, November 23, 2013 3:18 pm
Room: Moderated Discussions
none ( on November 18, 2013 3:59 am wrote:
> Nice article as usual :-)
> Just one comment:
> "Moreover, the L1D in Knights Corner was 32KB and 8-way associative to work with 4
> threads – the 6 way associativity in Silvermont is simply insufficient and would cause
> excessive conflicts."
> My understanding is that Intel use 6/8 ways no because of MT but to prevent having to
> use hardware alias handling for 4KB pages.

I think that's correct - Every Intel x86 core from the 486 on has had a VIPT L1 D$, with set size less than or equal to the smallest x86 page size of 4 KB. For example, the Core2 did not have SMT but did have an 8-way L1 D$.

With that said, it doesn't really diminish or argue against David's point. Regardless of how Intel got to high associativity to begin with, they wouldn't want to back off on that attribute in such an aggressively multi-threaded core.
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TopicPosted ByDate
Knights Landing CPU SpeculationDavid Kanter2013/11/18 02:03 AM
  Knights Landing CPU Speculationnone2013/11/18 02:59 AM
    Knights Landing CPU SpeculationPatrick Chase2013/11/23 03:18 PM
      Knights Landing CPU SpeculationAdam Kalisz2013/11/26 01:20 AM
        Over 2,000 mm^2 of eDRAM???Mark Roulo2013/11/26 09:28 AM
          Over 2,000 mm^2 of eDRAM???David Kanter2013/11/26 11:09 AM
          Over 2,000 mm^2 of eDRAM???Eric Bron2013/11/26 11:21 AM
            Over 2,000 mm^2 of eDRAM???tarlinian2013/11/26 11:50 AM
              Over 2,000 mm^2 of eDRAM???Eric Bron2013/11/26 01:07 PM
                Over 2,000 mm^2 of eDRAM???Eric Bron2013/11/26 01:09 PM
                Over 2,000 mm^2 of eDRAM???aaron spink2013/11/26 03:03 PM
                  Over 2,000 mm^2 of eDRAM???Eric Bron2013/11/26 11:42 PM
                    Over 2,000 mm^2 of eDRAM???aaron spink2013/11/27 10:31 AM
              Over 2,000 mm^2 of eDRAM???David Kanter2013/11/26 04:25 PM
                Over 2,000 mm^2 of eDRAM???tarlinian2013/11/26 07:01 PM
          Over 2,000 mm^2 of eDRAM???Eric2013/11/27 02:54 AM
            eDRAM is DRAM in a logic-oriented processPaul A. Clayton2013/11/27 07:10 AM
  Knights Landing CPU SpeculationJames2013/11/18 05:26 AM
    Knights Landing CPU SpeculationMichael S2013/11/18 02:57 PM
      Knights Landing CPU SpeculationUrban Novak2013/11/19 12:49 AM
        Knights Landing CPU Speculationnone2013/11/19 01:19 AM
          Knights Landing CPU SpeculationEric2013/11/19 07:48 PM
            Total GPGPU/Xeon Phi market maybe ~ $500M/year ...Mark Roulo2013/11/20 10:35 AM
      Knights Landing CPU SpeculationWes Felter2013/11/19 12:06 PM
        Knights Landing CPU SpeculationMichael S2013/11/19 12:49 PM
  Knights Landing CPU SpeculationEric2013/11/18 12:17 PM
    Knights Landing CPU SpeculationDaniel2013/11/19 02:28 AM
      Knights Landing CPU SpeculationEric2013/11/19 07:36 PM
      HPC guys score FLOPS non-obviouslyMark Roulo2013/11/20 10:43 AM
        3-TFlops-DGEMMMichael S2013/11/20 10:59 AM
          3-TFlops-DGEMMMark Roulo2013/11/20 12:22 PM
            3-TFlops-DGEMMDaniel2013/11/20 01:04 PM
              3-TFlops-DGEMMEric2013/11/21 01:28 AM
                3-TFlops-DGEMMMichael S2013/11/21 05:48 AM
                  3-TFlops-DGEMMRecessionCone2013/11/21 11:13 AM
                    3-TFlops-DGEMMMichael S2013/11/21 02:34 PM
                  3-TFlops-DGEMMEric2013/11/22 02:10 AM
                    3-TFlops-DGEMMMichael S2013/11/22 04:41 AM
                    A (not very sensible) alternative: FMADD + FADDPaul A. Clayton2013/11/22 08:19 AM
                  3-TFlops-DGEMMSylvain Collange2013/11/24 02:37 AM
                    3-TFlops-DGEMMMichael S2013/11/24 06:06 AM
                      3-TFlops-DGEMMSylvain Collange2013/11/24 09:28 AM
        HPC guys score FLOPS non-obviouslyPatrick Chase2013/11/23 02:58 PM
  Knights Landing CPU SpeculationPaul Caheny2013/11/18 01:25 PM
    Knights Landing CPU SpeculationKonrad Schwarz2013/11/19 12:24 AM
  Knights Landing CPU SpeculationAmiba Gelos2013/11/19 07:36 PM
    Knights Landing CPU SpeculationDavid Kanter2013/11/20 09:52 AM
    Knights Landing CPU SpeculationLinus Torvalds2013/11/21 02:12 PM
      Knights Landing CPU SpeculationAmiba Gelos2013/11/21 05:14 PM
      Knights Landing CPU SpeculationPatrick Chase2013/11/23 03:33 PM
        Knights Landing CPU SpeculationLinus Torvalds2013/11/25 11:29 AM
          Knights Landing CPU SpeculationLinus Torvalds2013/11/25 12:05 PM
          Knights Landing CPU SpeculationPatrick Chase2013/11/25 12:22 PM
            Knights Landing CPU SpeculationLinus Torvalds2013/11/26 10:11 AM
          Knights Landing CPU SpeculationEric2013/11/26 03:05 AM
            Knights Landing CPU SpeculationEric2013/11/26 03:15 AM
            Knights Landing CPU Speculationnone2013/11/26 03:33 AM
              Knights Landing CPU SpeculationEric2013/11/26 06:30 PM
                Knights Landing CPU SpeculationEric2013/11/26 06:34 PM
                  What is MCDRAM?anon2013/11/26 08:58 PM
                    What is MCDRAM?none2013/11/27 01:00 AM
                      What is MCDRAM?Klimax2013/11/27 02:19 AM
                  Knights Landing CPU SpeculationKlimax2013/11/26 11:06 PM
                Knights Landing CPU SpeculationKlimax2013/11/26 11:05 PM
            Knights Landing CPU Speculationanon2013/11/26 05:53 AM
              Knights Landing CPU Speculationnone2013/11/26 06:20 AM
                Knights Landing CPU SpeculationMichael S2013/11/26 08:06 AM
                  Knights Landing CPU Speculationnone2013/11/26 09:18 AM
                    Knights Landing CPU SpeculationEric Bron2013/11/26 01:21 PM
                      Knights Landing CPU SpeculationEric Bron2013/11/26 01:27 PM
                        Knights Landing CPU Speculationnone2013/11/26 02:26 PM
                    Knights Landing CPU Speculationanon2013/11/26 05:42 PM
                      Knights Landing CPU Speculationnone2013/11/27 01:08 AM
                        Knights Landing CPU Speculationanon2013/11/27 01:50 AM
                          Knights Landing CPU Speculationnone2013/11/27 01:58 AM
                      Knights Landing CPU SpeculationMichael S2013/11/27 01:25 AM
                        Knights Landing CPU Speculationanon2013/11/27 02:32 AM
                          Knights Landing CPU SpeculationMichael S2013/11/27 03:08 AM
    Knights Landing CPU SpeculationChung Leong2013/11/27 01:28 AM
      Knights Landing CPU SpeculationMichael S2013/11/27 02:53 AM
        Knights Landing CPU SpeculationChung Leong2013/11/27 01:03 PM
  BiG.LiTTLe for KNL?Jeff K2013/11/22 06:17 AM
    BiG.LiTTLe for KNL?Patrick Chase2013/11/23 02:54 PM
      BiG.LiTTLe for KNL?Patrick Chase2013/11/23 03:01 PM
  Transactional memoryPatrick Chase2013/11/23 02:37 PM
    Transactional memoryBhima2013/11/25 07:01 AM
      Transactional memoryPatrick Chase2013/11/25 11:52 AM
  Knights Landing CPU SpeculationDaniel2013/11/25 02:17 AM
    Knights Landing CPU SpeculationKlimax2013/11/25 03:12 AM
    Knights Landing CPU Speculationnone2013/11/25 04:05 AM
      Knights Landing CPU SpeculationKlimax2013/11/25 04:45 AM
        Knights Landing CPU Speculationnone2013/11/25 04:55 AM
          Knights Landing CPU Speculationgmb2013/11/25 07:21 AM
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