Date: Sat, 20 Dec 2003 12:40:12 +0100 From: Harald Schmalzbauer <h@schmalzbauer.de> To: Scott Long <scottl@freebsd.org>, Mike Tancsa <mike@sentex.net> Cc: stable@freebsd.org Subject: Re: to hyperthread or not to hyperthread Message-ID: <200312201240.19385@harrymail> In-Reply-To: <20031219152927.V47291@pooker.samsco.home> References: <6.0.1.1.0.20031219172103.092e4c90@209.112.4.2> <20031219152927.V47291@pooker.samsco.home>
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--Boundary-02=_jUD5/BwmKvY3MGK Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Description: signed data Content-Disposition: inline On Friday 19 December 2003 23:34, Scott Long wrote: > On Fri, 19 Dec 2003, Mike Tancsa wrote: > > We are replacing a box that is fairly busy with many different processes > > (sendmail / pop3). The new MB and CPU is hyperthreading capable. Is it > > worth it to enable this ? Does anyone have any real world experiences > > with it in RELENG_4 that say one way or the other to use or not use it ? > > > > dmesg shows, > > > > CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (2992.52-MHz 686-class CPU) > > Origin =3D "GenuineIntel" Id =3D 0xf29 Stepping =3D 9 > > =20 > > Features=3D0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,= PGE, > >MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,S SE2,SS,HTT,TM,PBE> > > Hyperthreading: 2 logical CPUs > > > > ---Mike > > HyperThreading usually requires special smarts in the OS process > scheduler so that the cores don't bottleneck each other with cache > thrashing and pipeline stalls/starvation. Without this, Hyperthreading > is usually slightly slower than non-Hyperthreading. 4.x does not have > a scheduler that understand HTT, but 5.2-CURRENT does. Do you mean ULE or 4BSD regarding HTT capable? Thanks, =2DHarry > > Scott > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" --Boundary-02=_jUD5/BwmKvY3MGK Content-Type: application/pgp-signature Content-Description: signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (FreeBSD) iD8DBQA/5DUjBylq0S4AzzwRAtHvAKCOxS6zbG1+wEv4z21yvwj8zB/qCACfag/k tukeEGqOH5JteI2xFkX0g98= =hvqg -----END PGP SIGNATURE----- --Boundary-02=_jUD5/BwmKvY3MGK--
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