From: John Weekes <lists.xen@nuclearfallout.net>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: "mark.langsdorf@amd.com" <mark.langsdorf@amd.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"Wang, Winston L" <winston.l.wang@intel.com>,
"Wei, Gang" <gang.wei@intel.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Performance difference between Xen versions
Date: Mon, 02 May 2011 20:39:50 -0700 [thread overview]
Message-ID: <4DBF7906.3030909@nuclearfallout.net> (raw)
In-Reply-To: <625BA99ED14B2D499DC4E29D8138F1505C885A8F4B@shsmsx502.ccr.corp.intel.com>
On 5/2/2011 8:04 PM, Tian, Kevin wrote:
>
> you won't know the exact frequency bumped up in the turbo mode, as it's all handled
> by the CPU itself. what xen can do is just to tell the cpu now I'm OK to enter turbo
> mode, which is 2268000 (1M higher than normal P0). Then CPU will decide whether
> current code can be overclocked based on various conditions, such as TDP, other
> core activities in the same package, ...
>
> One possibility to verify that turbo mode does work is to run a CPU intensive workload
> on one core, while keeping other cores mostly idle. Then choose cpufreq governor
> to be performance, and then compare your benchmark when BIOS turbo mode is
> on/off. This should give you some feeling whether turbo mode works on your platform.
Thanks for the response, Kevin.
It's good to know that I can check turbo by looking to see if it's in
the 1000hz-higher mode. It's a little strange to me that the true MHz
level of the turbo wouldn't be known/shown, but I can live with that, as
the actual performance is what counts. I'll run those benches.
-John
next prev parent reply other threads:[~2011-05-03 3:39 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-29 12:32 Performance difference between Xen versions Juergen Gross
2011-04-29 13:28 ` Keir Fraser
2011-04-29 13:35 ` Juergen Gross
2011-04-29 14:58 ` Keir Fraser
2011-04-29 16:10 ` Jan Beulich
2011-05-02 5:31 ` Juergen Gross
2011-05-02 6:41 ` Keir Fraser
2011-05-02 7:23 ` Jan Beulich
2011-05-02 8:00 ` Juergen Gross
2011-05-02 8:15 ` Jan Beulich
2011-05-02 8:23 ` Juergen Gross
2011-05-02 8:49 ` Keir Fraser
2011-05-03 3:06 ` Tian, Kevin
2011-05-06 13:49 ` Juergen Gross
2011-05-06 14:27 ` Jan Beulich
2011-05-11 6:08 ` Tian, Kevin
2011-05-11 6:23 ` Juergen Gross
2011-05-02 17:52 ` John Weekes
2011-05-02 18:12 ` Konrad Rzeszutek Wilk
2011-05-02 18:43 ` John Weekes
2011-05-02 19:16 ` John Weekes
2011-05-02 19:36 ` Konrad Rzeszutek Wilk
2011-05-02 19:54 ` John Weekes
2011-05-03 2:16 ` Tian, Kevin
2011-05-03 3:04 ` Tian, Kevin
2011-05-03 3:39 ` John Weekes [this message]
2011-05-03 7:23 ` Tian, Kevin
[not found] ` <4DBF13BB.3000309@nuclearfallout.net>
2011-05-03 7:23 ` Jan Beulich
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