lkml.org 
[lkml]   [2010]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectHyperthreading on Core i7s: To use or not to use?
    Hello,

    Should the 'correct' kernel [CPU] configuration for a core i7 860/870..?

    - Multi-core support
    - Cores: 8
    - SMT: Enabled/ON

    From CONFIG_SCHED_SMT:

    . SMT scheduler support improves the CPU scheduler's decision making .
    . when dealing with Intel Pentium 4 chips with HyperThreading at a .
    . cost of slightly increased overhead in some places. If unsure say .
    . N here. .

    Does this also 'help' and/or 'apply' as much when dealing with Core i7s?

    --

    Quick little benchmark (pbzip2 -9 linux kernel source), the benchmark is
    really within the noise (8 on/off)
    - Multicore(8)/HT(Off) = 73.72user 0.33system 0:09.50elapsed 779%CPU (0avgtext+0avgdata 458528maxresident
    - Multicore(8)/HT(On) = 74.28user 0.40system 0:09.67elapsed 772%CPU (0avgtext+0avgdata 428304maxresident
    - Multicore(4)/HT(On) = 68.76user 0.30system 0:17.44elapsed 396%CPU (0avgtext+0avgdata 213616maxresident)k

    --

    Has anyone done any in-depth benchmarking for the core i7s that have multiple
    cores and HT disabled/enabled?

    Justin.


    \
     
     \ /
      Last update: 2010-01-26 11:05    [W:4.087 / U:0.960 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site