From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19673 invoked by alias); 8 Dec 2011 13:15:07 -0000 Received: (qmail 19659 invoked by uid 22791); 8 Dec 2011 13:15:05 -0000 X-SWARE-Spam-Status: No, hits=-1.0 required=5.0 tests=AWL,BAYES_00,SPF_NEUTRAL X-Spam-Check-By: sourceware.org Received: from smtp0.epfl.ch (HELO smtp0.epfl.ch) (128.178.224.219) by sourceware.org (qpsmtpd/0.43rc1) with SMTP; Thu, 08 Dec 2011 13:14:52 +0000 Received: (qmail 20327 invoked by uid 107); 8 Dec 2011 13:14:48 -0000 Received: from 69-196-173-194.dsl.teksavvy.com (HELO [192.168.0.100]) (69.196.173.194) (authenticated) by smtp0.epfl.ch (AngelmatoPhylax SMTP proxy) with ESMTPA; Thu, 08 Dec 2011 14:14:49 +0100 Message-ID: <4EE0B848.80206@cs.utoronto.ca> Date: Thu, 08 Dec 2011 13:15:00 -0000 From: Ryan Johnson User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: Machine very sluggish while compiling References: <4ECEE88E.5050307@cs.utoronto.ca> <20111125154751.GP28395@trikaliotis.net> <4EDB2761.6040508@cs.utoronto.ca> <20111204100639.GA9849@calimero.vinschen.de> <4EE09CF8.7040804@bellsouth.net> In-Reply-To: <4EE09CF8.7040804@bellsouth.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com X-SW-Source: 2011-12/txt/msg00184.txt.bz2 On 08/12/2011 6:18 AM, Robert Miles wrote: > On 12/4/2011 4:06 AM, Corinna Vinschen wrote: >> Anyway, stoppping the PCA service and setting its start mode to "Manual" >> does the trick for me. While I was at it I also disabled Superfetch, >> which drops the memory usage of this svchost to a fraction of what it >> used before, and the CPU usage to 0%, and I don't see any performance >> difference. > Are you aware that the Superfetch service deliberately tries to use > most of the > memory not otherwise in use as a cache for the most frequently > accessed disk > files, in order to speed up accesses to those files? I've found it > rather slow to > release this cache memory when some other program needs it, though. In my experience Superfetch does a phenomenally bad job of predicting which files I (or my wife) actually plan to use. The machine is sluggish not (just) because the memory is uselessly tied up, but because the disk is constantly busy fetching data that will never be used and penalizes access to the data I actually do need. The memory wastage just compounds the problem by contributing additional swapping on top of all this other extra disk activity. Both computers at my house saw *significant increases* in performance and responsiveness when I disabled Superfetch a few months ago. Ryan -- 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