From owner-freebsd-questions@freebsd.org Thu Sep 10 17:42:40 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 58BF3A00AC2 for ; Thu, 10 Sep 2015 17:42:40 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: from mail-qg0-f52.google.com (mail-qg0-f52.google.com [209.85.192.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 18CEB1D58 for ; Thu, 10 Sep 2015 17:42:39 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: by qgt47 with SMTP id 47so41748659qgt.2 for ; Thu, 10 Sep 2015 10:42:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:content-transfer-encoding:message-id:references:to; bh=LTy8ErdzHq5svfY+nBaZrZFP46T+ZB04XAih+XoWG+U=; b=ibA9yXUA+t6XIbonr0xOdg8pn+LCUwj+SOB2xzeIhrNp/Fy2X3cv3x084IkPErBYCz 1gHT+XNd1M2CFxlQsj3F/A6j2zXvxi7y1vPSgg45vFL0i5KmUlIUa4AMNFeB7GRmGLt1 QIOfCKPd+q9dPp7H5sBIHeT9qY55f99WQmaQxYtsUcmkgknSRN7Skx2rQZg9drwOXpeN yKiYlqz9cFUvcoi1UPXLfCjf4/iY5WFIoKQ0e1mfG/Q5ViScja23ISkfe5FVOQxzxm2P ATA/2D7Co2tmXP/Pf0TL0N/nVLT4FIfXbAX0V65xIeEN0BwK0H1XAhhtzvOxvvmD4hQR peMQ== X-Gm-Message-State: ALoCoQkNkrxdHDpE3KGNukV9Qv9Pa+vYvrk+oVzPBUzXAeUZxKGLCGVqawXkKMibyP23Y52Gb+bR X-Received: by 10.140.33.225 with SMTP id j88mr55020083qgj.30.1441906958672; Thu, 10 Sep 2015 10:42:38 -0700 (PDT) Received: from [192.168.2.138] (pool-100-4-179-8.albyny.fios.verizon.net. [100.4.179.8]) by smtp.gmail.com with ESMTPSA id g20sm6367143qge.9.2015.09.10.10.42.36 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Sep 2015 10:42:36 -0700 (PDT) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: Replacing Drive with SSD From: Paul Kraus In-Reply-To: <867fnywc8i.fsf@WorkBox.Home> Date: Thu, 10 Sep 2015 13:42:35 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: <08306F31-955B-4710-B20B-4F2ABE0CBA56@kraus-haus.org> References: <20150829220311.c7608be1.freebsd@edvax.de> <55E45973.2050103@sneakertech.com> <55E4865B.1000104@sneakertech.com> <20150831181135.7682a810@gumby.homeunix.com> <867fnywc8i.fsf@WorkBox.Home> To: FreeBSD Questions X-Mailer: Apple Mail (2.1878.6) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Sep 2015 17:42:40 -0000 On Sep 10, 2015, at 11:00, Brandon J. Wandersee = wrote: > Leaving blocks unpartitioned doesn't mean those blocks won't be = written > to; it just ensures that a certain amount of space (and so a certain > number of blocks/cells) must always be free, forcing writes to be = spread > across different physical portions of the disk in a relatively even > manner. It's my understanding that this over-provisioning isn't > exactly necessary in most SSDs nowadays. It just serves as a stronger > guarantee than entrusting everything to a drive's firmware. Each SSD model has some amount of over provisioning built in. The more = expensive, Enterprise grade SSDs have more (in many cases much more) = than the cheaper consumer units. So based on the performance you need = and the SSD you have, it is still prudent to manually over provision = with unpartitioned space. Note that some vendors will tell you about their over provisioning and = others don=92t. -- Paul Kraus paul@kraus-haus.org