From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1S4fgI-0006WF-Hm for garchives@archives.gentoo.org; Mon, 05 Mar 2012 21:42:58 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 7BD5EE0652; Mon, 5 Mar 2012 21:42:39 +0000 (UTC) Received: from mail-wi0-f181.google.com (mail-wi0-f181.google.com [209.85.212.181]) by pigeon.gentoo.org (Postfix) with ESMTP id A5C7CE05F1 for ; Mon, 5 Mar 2012 21:41:14 +0000 (UTC) Received: by wico1 with SMTP id o1so1973776wic.40 for ; Mon, 05 Mar 2012 13:41:13 -0800 (PST) Received-SPF: pass (google.com: domain of markknecht@gmail.com designates 10.180.102.129 as permitted sender) client-ip=10.180.102.129; Authentication-Results: mr.google.com; spf=pass (google.com: domain of markknecht@gmail.com designates 10.180.102.129 as permitted sender) smtp.mail=markknecht@gmail.com; dkim=pass header.i=markknecht@gmail.com Received: from mr.google.com ([10.180.102.129]) by 10.180.102.129 with SMTP id fo1mr3969865wib.6.1330983673847 (num_hops = 1); Mon, 05 Mar 2012 13:41:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=IwcWYbub/cgLJ8BzSaXWw/zmMq6xXXn4V9Ui5ttMcxE=; b=Om0lwClJxs+N5bRHER144NJCt+UMOLeHLBkbYL2Q9G1g/xV2qIfyAJVyjWxuGfZn6j LU4jSoEWGW1CyRjlDywoE8QIknRr11rW33LGap/V6GVH+VQZ+reKybrkzr2NRH+oe52m BdS2H8SJhFipOaGOLkQNQUpb+JMOyn7quuHlrxHD9i63CyZUia3Xjk5esM9z5SCPpq2t 3IOaL7xopDi+4sxVA4oAlZaPEWlZfN8i62OlOHRFMm9YtfGL5aRucH9ultqglK2rfQIy DCjuzl1XtA07bmZoQoLm3z/TrOy4QBzTEL+19eDzUTtvd3l+7PjROZkfb6hlxWZZxjAf mgOQ== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.180.102.129 with SMTP id fo1mr3159119wib.6.1330983673787; Mon, 05 Mar 2012 13:41:13 -0800 (PST) Received: by 10.223.2.194 with HTTP; Mon, 5 Mar 2012 13:41:13 -0800 (PST) In-Reply-To: References: Date: Mon, 5 Mar 2012 13:41:13 -0800 Message-ID: Subject: Re: [gentoo-user] Re: Gentoo on a Dell XPS 13 Ultrabook From: Mark Knecht To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: f2b8e01d-103f-4d8d-9502-da96725a3e97 X-Archives-Hash: 6758def622450c1c45de1c20a8855240 On Sun, Mar 4, 2012 at 6:06 PM, Pandu Poluan wrote: > > On Mar 5, 2012 4:59 AM, "Grant" wrote: >> >> >> All my drives says this from fdisk: >> >> Units = sectors of 1 * 512 = 512 bytes >> Sector size (logical/physical): 512 bytes / 512 bytes >> I/O size (minimum/optimal): 512 bytes / 512 bytes >> >> So it doesn't matter where the first partition starts? >> > > Older BIOSes don't understand that hard disks now can have 4KiB sectors, so > some of the "advanced format" hard disks report a sector size of 512B. But > behind the scenes, the hard disk maps the logical sector to a subsector of > the physical sector. > > The only sure fire way to find out if your hard disk uses 4KiB sectors is to > open your computer and eyeball the hard disk. All 4KiB hard disks that I > know of have statements on their surface that tell me so. > > Rgds, I think I must be kind of late to this conversation, but as background consider hdparm -i coupled with Google for the actual spec: c2stable ~ # hdparm -i /dev/sdg /dev/sdg: Model=WDC WD10EARS-00Z5B1, FwRev=80.00A80, SerialNo=WD-WCAVU0415076 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq } RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=50 BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=off CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=1953525168 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio3 pio4 DMA modes: mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 AdvancedPM=no WriteCache=enabled Drive conforms to: Unspecified: ATA/ATAPI-1,2,3,4,5,6,7 * signifies the current active mode c2stable ~ # With the model number it takes only a minute to determine that this WD drive is a 4K sector drive. (Which is marked on the drive, as you state, but I'd have to remove it to find that out.) Now, in terms of performance, the only requirement (as I understand it) is that all drive partition be aligned to sector addresses divisible by 8. (512 * 8 = 4K) The reason 63 gives low performance is because it's not naturally aligned by 8. With older versions of fdisk if I started the first partition at 64 then the performance was fine and only one sector was wasted. M$, for whatever reason, decided to start at 2048, which is divisible by 8, reserving the area at the front of the drive for (I think) their boot loader and other M$-y things. My understanding of why fdisk now enforces this is simply to be more careful about not overwriting the M$ boot loaderif it's there. (But I could be very wrong about that!) Remember, it's possible to make a dual boot system using M$'s loader instead of grub, and important that fdisk doesn't mangle it when someone is using that tool. Just my views, Mark