From owner-freebsd-current@FreeBSD.ORG Mon Mar 18 10:57:31 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id C54FD1EA2 for ; Mon, 18 Mar 2013 10:57:31 +0000 (UTC) (envelope-from m.e.sanliturk@gmail.com) Received: from mail-ie0-x233.google.com (mail-ie0-x233.google.com [IPv6:2607:f8b0:4001:c03::233]) by mx1.freebsd.org (Postfix) with ESMTP id 9ADF5884 for ; Mon, 18 Mar 2013 10:57:31 +0000 (UTC) Received: by mail-ie0-f179.google.com with SMTP id k11so6689852iea.38 for ; Mon, 18 Mar 2013 03:57:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=fAVBUY/Mrnj7hWje2080jmvxAgdXDl0liwaXhoSd10I=; b=xksiPouP68X1XJDqO5M2MLRaxIm4v6nqbAeEq7+rk8Cx+9zBEhyYBNrLZMdbxCcD/W mZjUOAeyTBMmTt1Jg2vZJnsjwjtBRTKXvnrIpjLe4W2Xc8TlOPJ6U4p3UIRT5039UC3I JC080M2e3LjdVZRKe0J0ksUU3uAIpD/WGSAAJjF3+Nd06fuiWOzegcO6EwqX3UUQn8TJ 2foTD+lD+mzDAA26OF8f9RN6H0LH4Bz+FGmpwg+jDDS+r61peadKlfqTBNNRtZlovjDo mkPVi+yKcDWYswhJSOQtYnbaGyvR8+raXDkFmLi4OS1NGrvRKMJARIi+unfx/6avzgXY FvzQ== MIME-Version: 1.0 X-Received: by 10.50.6.3 with SMTP id w3mr5839899igw.76.1363602640165; Mon, 18 Mar 2013 03:30:40 -0700 (PDT) Received: by 10.64.107.162 with HTTP; Mon, 18 Mar 2013 03:30:40 -0700 (PDT) In-Reply-To: References: Date: Mon, 18 Mar 2013 03:30:40 -0700 Message-ID: Subject: Re: FreeBSD is very slow when Memory chip sizes are imbalanced in slots From: Mehmet Erol Sanliturk To: Tom Evans Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: freebsd-current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Mar 2013 10:57:31 -0000 On Mon, Mar 18, 2013 at 3:01 AM, Tom Evans wrote: > On Sun, Mar 17, 2013 at 8:26 PM, Mehmet Erol Sanliturk > wrote: > > Dear All , > > > > Previously , in the following message , I have mentioned effect of memory > > chip placement on execution speed : > > > > > http://lists.freebsd.org/pipermail/freebsd-current/2012-February/031836.html > > Effect of Processor and Memory on KDE4 execution > > speed< > http://lists.freebsd.org/pipermail/freebsd-current/2012-February/031836.html > > > > These seems to be more than different memory slot allocation between > those two boxes. > > Can you reproduce this on the one labelled 'FAST' by assigning memory > in the same manner as it is assigned in the one labelled 'SLOW'? > > > > > > > The above thread did not produce any usable result . > > > > The problem is persisting over 9.1 and 10.0 current . > > > > My opinion is that , it is NOT related to KDE only . > > > > After X is started , any desktop is behaving very slowly . > > This is also visible in PC-BSD and GhostBSD . > > This is very nebulous. What is 'very slowly'? Is there a test you can > run that is independent of X, KDE, etc that demonstrates this? > > One thing that KDE does require (iirc - from about 5 years ago, > probably wrong now) is that since KDE is C++, it spends a lot of time > loading executables/libraries into memory and prelinking them. If you > have dramatically lowered your RAM bandwidth, then this stage could > take a lot longer. > > One thing that could cause memory bandwidth to lower is by installing > mismatched modules. The BIOS will set all RAM up at the same speed, > the lowest that all of the installed RAM supports. If you fill the RAM > slots with mismatched modules of different sizes, it may also not > enable dual channel memory, further reducing the RAM bandwidth. > > Because of this, I think it is a jump to go from "My computer runs > slow when I put these bits of RAM in" to "FreeBSD always runs slow > when there is mismatched RAM". > > If you find out what is slow on FreeBSD - eg RAM bandwidth - you can > then test the same thing in Linux. If Linux shows the same slowdown > from fast to slow, then I'm sorry, that's a hardware defect. If, on > the other hand, Linux is just as fast in both configurations, then I'm > sure a lot of people would be interested as to why. > > Cheers > > Tom > I think , all of the answers to your questions may be found in the above referenced thread messages : Every possible combination has been tried , and identified that the problem is different memory chip sizes for FreeBSD ( v9.0 , v9.1 , v10.0 ) ( GhostBSD , PC-BSD , v9.0 , v9.1 ) : Channel A : Slot 1 : 2 GB Slot 2 : 1 GB Channel B : Slot 1 : 2 GB Slot 2 : 1 GB All of the memory chips : Kingston HyperX , same clock frequency . Memory placement kind is correct . There is NO any hardware defect . Linux is insensitive to such different memory chip sizes ( I am using Fedora , CentOS , Mandriva , Mageia , OpenSUSE , Arch Linux , Puppy Linux , and some others ... ) Thank you very much . Mehmet Erol Sanliturk