From: Justin Piszcz <jpiszcz@lucidpixels.com>
To: linux-kernel@vger.kernel.org
Subject: Hyperthreading on Core i7s: To use or not to use?
Date: Tue, 26 Jan 2010 05:02:08 -0500 (EST) [thread overview]
Message-ID: <alpine.DEB.2.00.1001260456210.14707@p34.internal.lan> (raw)
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.
next reply other threads:[~2010-01-26 10:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-26 10:02 Justin Piszcz [this message]
2010-01-26 10:56 Daniel J Blueman
2010-01-26 13:11 ` peng huang
2010-01-27 0:50 ` J.A. Magallón
2010-01-29 22:59 ` Henrique de Moraes Holschuh
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