From: Dave Jones <davej@redhat.com>
To: Xiaoning Ding <dingxn@ymail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: a question about p4_clockmod module on Xeon quad core processors
Date: Thu, 29 Jan 2009 12:08:59 -0500 [thread overview]
Message-ID: <20090129170859.GA3162@redhat.com> (raw)
In-Reply-To: <213679.55387.qm@web59907.mail.ac4.yahoo.com>
On Thu, Jan 29, 2009 at 08:32:41AM -0800, Xiaoning Ding wrote:
> > > Thanks for the correction.
> > > My experiments need to reduce CPU speed. However, I
> > can only reduce the speed by about 30% (from 2.67GHz to
> > 2GHz) with ACPI. That is not enough for the experiments.
> >
> > The ACPI P-states are nearly always correct, so you
> > won't be
> > able to go below 2GHz on this system.
>
> That's true for changing P-States with ACPI. But I can still get slower speed with clock modulation, right?
Clock modulation will lower the performance, but the clock speed
will remain constant.
Dave
--
http://www.codemonkey.org.uk
next prev parent reply other threads:[~2009-01-29 17:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-27 20:17 a question about p4_clockmod module on Xeon quad core processors Xiaoning Ding
2009-01-27 21:23 ` Arjan van de Ven
2009-01-29 16:12 ` Xiaoning Ding
2009-01-28 21:02 ` Dave Jones
2009-01-29 2:06 ` Xiaoning Ding
2009-01-29 2:45 ` Dave Jones
2009-01-29 16:32 ` Xiaoning Ding
2009-01-29 17:08 ` Dave Jones [this message]
2009-01-29 12:27 ` Michael Tokarev
2009-01-29 17:24 ` Dave Jones
2009-01-29 19:40 ` Xiaoning Ding
2009-01-29 19:54 ` Dave Jones
2009-01-28 21:05 ` Wes Felter
2009-01-29 2:11 ` Xiaoning Ding
2009-01-29 20:47 ` Wes Felter
2009-01-30 1:12 ` Xiaoning Ding
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