X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=0.9 required=5.0	tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SARE_MSGID_LONG45,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: sourceware.org
MIME-Version: 1.0
Date: Tue, 4 May 2010 18:34:38 -0700
Message-ID: <p2r988dc97d1005041834hc39fad3au5b65dc5b6a009bbc@mail.gmail.com>
Subject: cpu usage capped?
From: Ross Anderson <rpanderson AT gmail DOT com>
To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset=ISO-8859-1
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

Hi all,

I have some code that takes advantage of 8 cores on my machine using
OpenMP. Under plain ol windows, this code causes all the CPUs to max
out at 99%. But when recompiled for cygwin, each core jumps to about
85%. The rest is not being used by other processes. Could someone
explain why this is the case?

Thanks

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple