X-Spam-Check-By:	sourceware.org
Message-ID:	<45886CC1.9070002@t-online.de>
Date:	Tue, 19 Dec 2006 23:50:41 +0100
From:	Christian Franke <Christian DOT Franke AT t-online DOT de>
User-Agent:	Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.7) Gecko/20060910 SeaMonkey/1.0.5
MIME-Version:	1.0
To:	cygwin AT cygwin DOT com
Subject:	Re: Cygwin slower on one computer
References:	<45804D3A DOT 6060602 AT algonet DOT se> <4582CA47 DOT 2070407 AT algonet DOT se>
In-Reply-To:	<4582CA47.2070407@algonet.se>
X-ID:	SyGeRmZUgewWYP4RB0IEJUamrVzG6acvGuxjNdj14DF1OnhyCHrOEa
X-TOI-MSGID:	07614cfc-41c7-4a6d-a5a1-393659f1fe60
X-IsSubscribed:	yes
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

Magnus Holmgren wrote:

> ...
> After some more digging - and a bit of feedback off-list - I get the 
> feeling (in the cases I've noticed at least) that the speed difference 
> is mainly explained by the following reasons (in no particular order):
>
> * fork is expensive.
> * vfork is just a wrapper for fork on cygwin.
> * fork is much more expensive on AMD than on Intel.
>
> The third one is the one I'm most unsure about, as I only really have 
> data about one Intel architecture (the Pentium M). But on the AMD 
> system, the page fault delta (as reported by Process Explorer) during 
> a build is a little more than 10,000 per second, while on the Intel 
> system, the page fault delta can go to 30,000 per second.


Below are results for two PC with Intel P4 3200 ("Prescott") and 
Athlon64 3200+ ("Winchester").
Both with 1GB, WinXP SP2, Cygwin 1.5.22, Virus Scanner + Personal FW off:

Command: "time ./configure && time make" (on smartmontools source)

CPU    Intel     AMD

./configure:
real   1m09.0    5m25.8
user   0m53.5    0m54.2
sys    0m10.5    1m48.2

make:
real   0m15.3    0m25.6
user   0m10.9    0m09.3
sys    0m02.5    0m07.4


Disabling HT on Intel makes no difference.

Looks like fork is *much* more expensive on AMD. Any idea why?

Christian


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

- Raw text -