From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <gentoo-user+bounces-181072-garchives=archives.gentoo.org@lists.gentoo.org>
Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80])
(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
(No client certificate requested)
by finch.gentoo.org (Postfix) with ESMTPS id AF11C139083
for <garchives@archives.gentoo.org>; Tue, 5 Dec 2017 04:17:27 +0000 (UTC)
Received: from pigeon.gentoo.org (localhost [127.0.0.1])
by pigeon.gentoo.org (Postfix) with SMTP id CEDCBE0DA6;
Tue, 5 Dec 2017 04:17:20 +0000 (UTC)
Received: from mail-yb0-x241.google.com (mail-yb0-x241.google.com [IPv6:2607:f8b0:4002:c09::241])
(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
(No client certificate requested)
by pigeon.gentoo.org (Postfix) with ESMTPS id 6C3E4E090A
for <gentoo-user@lists.gentoo.org>; Tue, 5 Dec 2017 04:17:20 +0000 (UTC)
Received: by mail-yb0-x241.google.com with SMTP id j7so2936087ybl.3
for <gentoo-user@lists.gentoo.org>; Mon, 04 Dec 2017 20:17:20 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=gmail.com; s=20161025;
h=mime-version:in-reply-to:references:from:date:message-id:subject:to;
bh=NvvTixmmFme1e7UZJvTbNiQGtOrUTusR9bZQbaX80dY=;
b=igb7N367y6sbt8ma6pCmUrZ9inDQVkdovpVzISI6nFvr6hcJSwNcAVzeCES468fxBP
mS+5DsWNDBCkkI55+B8h0eYt+b099Z8Mvafe1Xq1fu66sii9mUA5MAL/Omzqvnh8oKcQ
TDkj4Vm3LrXdr6ccRF4iVrccmgdTm+AbGr5xa2aUFpKFF/hCO5/t4hMc1CAoyJaEM5gI
DtZs19nA3ft7E2+1WBmpWgafjjWT4DsGPgQRZTMcKT/1RS+U1x/klxTt5+cjIVlif09A
ZPs53s682u6BpctcfVfLUwyqVjY3yRylNxntGY/wf7epR5IbOLBuqSi1CAKrVnPm/Tke
k+VA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:in-reply-to:references:from:date
:message-id:subject:to;
bh=NvvTixmmFme1e7UZJvTbNiQGtOrUTusR9bZQbaX80dY=;
b=RtW2yTGeFxV0iUs3OpJCN8r1fcR1Ri7COEu8ZGu45Y6gi3uBmfGlelm788T65TZjuA
7qZ003jdSP++h49dGRYRYdvrnRAKJ64aJbBIy/f8g1lHC/ILurc4Mi0Tvtb8gvXnj6Xv
GLcWuJW2R8WTWlvxvk7/W5HEWIEI1omgb6KGN3DiMPPckVxz9kXNU/VVsnP/fFAfVIkq
s01uEIoBikAYdaqwhGA8evsD6gcKdb6nh4ITJjjCFlv2m21a80Qfzmd5gIL3MKJTxb0I
g5rKOnr0t/lGJV0bvp94jyEB4rNjpvozgRZyCrMq5bLxC2FuEzltcVNeoW6kH5i3RYg6
ZGzw==
X-Gm-Message-State: AJaThX6UrCB0ngIcLr48mWZwyMYfHJoZMoW4A6Uc2Up6/P2Lba0oWCcG
RM45NN6m4pIRSeDn5ofYercy4WtZ/ZyqIdercc4=
X-Google-Smtp-Source: AGs4zMaPLrN+x8Vvf5RYw9yNXl3yjHpQlvgWUjLBVzZno0EE7dX+S10oUfC+QNTdS9qzK0NnWWZY6y3RX36PTnjvdGo=
X-Received: by 10.37.92.84 with SMTP id q81mr12065900ybb.180.1512447438924;
Mon, 04 Dec 2017 20:17:18 -0800 (PST)
Precedence: bulk
List-Post: <mailto:gentoo-user@lists.gentoo.org>
List-Help: <mailto:gentoo-user+help@lists.gentoo.org>
List-Unsubscribe: <mailto:gentoo-user+unsubscribe@lists.gentoo.org>
List-Subscribe: <mailto:gentoo-user+subscribe@lists.gentoo.org>
List-Id: Gentoo Linux mail <gentoo-user.gentoo.org>
X-BeenThere: gentoo-user@lists.gentoo.org
Reply-to: gentoo-user@lists.gentoo.org
MIME-Version: 1.0
Received: by 10.13.234.16 with HTTP; Mon, 4 Dec 2017 20:17:18 -0800 (PST)
In-Reply-To: <f50301da-6138-ae94-5d45-658f09faf9cd@gmx.com>
References: <6b5fbeca-453c-f103-5e4e-a8db83a6dabf@st.com> <DM5PR15MB1722692DF2A8290D1BA46A47F0200@DM5PR15MB1722.namprd15.prod.outlook.com>
<5A158B10.6090007@youngman.org.uk> <6661527.9k004Oio64@eve> <f50301da-6138-ae94-5d45-658f09faf9cd@gmx.com>
From: R0b0t1 <r030t1@gmail.com>
Date: Mon, 4 Dec 2017 22:17:18 -0600
Message-ID: <CAAD4mYi_FYiNeMHSq2ziv9dBezwOZRiGTvxMX17P3Qt2PodbzA@mail.gmail.com>
Subject: Re: [gentoo-user] is multi-core really worth it?
To: gentoo-user@lists.gentoo.org
Content-Type: text/plain; charset="UTF-8"
X-Archives-Salt: daa9e43a-2bc4-4729-a714-a27029635786
X-Archives-Hash: 5a5b18af6f6cd6861a4c4e2f58a1a3e6
On Mon, Dec 4, 2017 at 10:11 PM, Taiidan@gmx.com <Taiidan@gmx.com> wrote:
> On my 16 core opteron I have to do -j32 or sometimes -j64 to be using
> everything all the time, is this normal? If I don't do this it won't be
> pegged at 100% all the time.
>
I use a ramdisk and anything over -j${NCPU} (incl. hyperthreaded
cores) causes performance degradation in general due mainly to the
compiling step. For some package sets I have noticed that higher build
parallelism helps due to some ebuild steps not being easily
parallelizable.
> I assume using a ramdisk would help with this? I wouldn't want to do a SSD
> as I assume it would excessively wear by doing compiles.
>
It should. While builds on an SSD will wear the SSD, comparing the
write volume to the expected drive lifetime will tell you the true
impact. It is (if I remember) still relatively small.
Cheers,
R0b0t1