From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 93E191381F3 for ; Thu, 29 Aug 2013 18:07:09 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id AD973E0E5F; Thu, 29 Aug 2013 18:07:06 +0000 (UTC) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id E4584E0E47 for ; Thu, 29 Aug 2013 18:07:05 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1VF6cY-00042b-GF for gentoo-amd64@lists.gentoo.org; Thu, 29 Aug 2013 20:07:02 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 29 Aug 2013 20:07:02 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 29 Aug 2013 20:07:02 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-amd64@lists.gentoo.org From: Duncan <1i5t5.duncan@cox.net> Subject: [gentoo-amd64] Re: Hard drive (installation) Date: Thu, 29 Aug 2013 18:06:45 +0000 (UTC) Message-ID: References: <521E4E74.9020005@jamadots.com> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@lists.gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: ip68-231-22-224.ph.ph.cox.net User-Agent: Pan/0.140 (Chocolate Salty Balls; GIT 3b8c3f7 /usr/src/portage/src/egit-src/pan2) X-Archives-Salt: fbfc1610-f4d5-4e95-8ef6-cfce1fb35830 X-Archives-Hash: 0070093523ba7041f7b2635cb8bcd65f Henry W. Peters posted on Wed, 28 Aug 2013 15:24:36 -0400 as excerpted: > So my question is: will an external HD work (I do audio > editing/recording/graphics) as a system/work space? & more importantly, > will Gentoo install on such a HD (external, usb 3)) USB-3 bus-speed, 5 Gbit/sec full duplex (previous USB was half-duplex and USB-2 was 480 Mbit/sec), tho "reasonable" thruput is 3.2 Gbit/sec (400 MByte/sec), according to wikipedia, should be much faster than a "spinning rust" hard drive, and indeed, should be reasonable as an SSD bus, as well, altho SATA 3 (aka SATA 600) is a bit faster (6 Gbit/sec, 600 MByte/sec), and a good speed SSD bottlenecks on the SATA 3 bus. By comparison, PCIE 1.x is 5 Gbit/sec at 2X, with PCIE 2.x 5 Gbit/sec at 1X and PCIE 3.x 8 Gbit/sec at 1X. Meanwhile, while drives do have a few megabyte of buffer (typically 16 or 32 MB), typical to-platter transfer rates run perhaps a quarter of that (100 MByte/sec is quite good). So you should EASILY be able to double-up on the "spinning rust" drives on USB 3 and still have plenty of bandwidth to spare, tho SATA 2 was indeed a bottleneck. If you're running a fast SSD, a dedicated USB 3 port will bottleneck on it compared to SATA 3, but not horribly so, and it will still be MUCH faster than spinning rust. Meanwhile, wikipedia's device bitrate table[1], from which I got the above, also lists audio bitrates. CDA: 1.411 Mbit/sec. S/PDIF: 3.072 Mbit/sec, AC'97 12.288 MBit/sec. Even full-rate HDMI audio should be no problem, at 36.864 Mbit/sec. Even USB 2 (480 Mbit/sec) should have absolutely no problem with that, which is why USB sound cards are viable and there's even some reasonably high end versions. Uncompressed video, OTOH, could be a bit of a different story. HDMI 1.0 and single-link DVI are both 4.95 Gbit/sec, so will stress USB 3 and SSDs. Full-speed dual-link DVI is 8.03 Gbit/sec, and HDMI 1.3 is 10.2 Gbit/sec, which will challenge any consumer-level storage today. PCIE of sufficient version and/or X can handle it (thus the common 16X PCIE graphics cards), but you'll be paying a pretty penny for storage of any significant size that can keep up! Which of course is why pretty much all video of significant resolution and frame-rate is also significantly compressed -- it's pretty much unmanageable, storage-wise, otherwise. But it doesn't sound like you're doing that heavy video or you'd not be worried about sound at all. Meanwhile, there's the whole "will it boot" question. However, as someone else mentioned, MS Windows 8 almost certainly means UEFI, which should be pretty flexible, provided of course that you're not running the MS side too locked down (MS requires that UEFI be user unlockable on amd64 for certification, so you should be able to unlock it). But beware, there are some USB drives that won't boot, at least not on BIOS (I'm not sure about UEFI). One way around that is to stick grub or whatever, along with the kernel (so basically your /boot) on a bootable thumbdrive (which you can stick in a USB 2 slot since for just grub speed isn't a huge issue) and boot it, then point the kernel at the otherwise unbootable USB drive for root, since the kernel should be able to handle even otherwise unbootable drives, once it's loaded. That's what I'm doing here with my external-drive level of bootable system backup, since the drive isn't otherwise bootable. --- [1] https://en.wikipedia.org/wiki/List_of_device_bit_rates -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman