Gentoo Archives: gentoo-amd64

From: Duncan <1i5t5.duncan@×××.net>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] Re: Hard drive (installation)
Date: Sat, 31 Aug 2013 01:41:30
Message-Id: pan$6ef98$70058058$78799247$722cd31d@cox.net
1 Rich Freeman posted on Thu, 29 Aug 2013 15:56:10 -0400 as excerpted:
2
3 > On Wed, Aug 28, 2013 at 3:24 PM, Henry W. Peters <hwpeters@××××××××.com>
4 > wrote:
5 >> So my question is: will an external HD work (I do audio
6 >> editing/recording/graphics) as a system/work space? & more importantly,
7 >> will Gentoo install on such a HD (external, usb 3))
8 >>
9 >>
10 > You did mention USB3, as did others in this thread. Hopefully this is
11 > obvious to all, but under no circumstances should you try to run an OS
12 > on USB2 or less.
13
14 People did it for years before USB3 and SATA2/3 arrived... and they did
15 it without the gigs of RAM often available for cache these days, too. It
16 certainly shouldn't be slower now than it was then, and with anything
17 even close to reasonable in terms of modern memory size (once we're
18 measuring in gigs, preferably 2+ but even a gig will help quite a bit),
19 it should be quite fast once the base system gets loaded.
20
21 Actually, USB2 is 480 Mbit/sec (as mentioned in my other reply), so
22 should do probably 30-40 MB/sec transfer, as long as it's the only thing
23 on the USB port. Sure, spinning rust storage is rated higher for
24 sequential I/O, but it's not /that/ much faster for random access due to
25 seek times. A good spinning rust disk might do twice that on good SATA
26 if you're lucky, not much more, particularly if it and the machine in
27 general are of USB2 or earlier vintage. So USB2 is likely to be a bit
28 slower with spinning rust, but not hugely so. And again, once the data's
29 in cache...
30
31 Just don't try to use the same USB2 port via hub or whatever to handle
32 keyboard/mouse/whatever-else as well.
33
34 But USB1.1 ... yes, THAT's slow!
35
36 And a good SSD would work on USB2, but I'm not sure why one would do it,
37 unless one had a spare laying around gathering dust... For that you
38 definitely want USB3 or SATA3 (tho SATA2 is half SATA3 speed so should
39 still be noticeably faster than spinning rust or USB2).
40
41 > eSATA or USB3 should in theory be fine, though I have
42 > no experience with the latter (I guess in theory it should work fine).
43 >
44 > Sure, any USB will work, but for USB2 or lower you'll start to get an
45 > experience that feels more like booting off of a LiveCD.
46
47 ... Which as I said isn't too bad once it either loads to RAMDisk or gets
48 cached, as long as there's enough memory for that, of course, but 2+ gigs
49 should be quite reasonably usable, and most anything half modern should
50 have that, unless we're talking embedded, something like a router.
51
52 --
53 Duncan - List replies preferred. No HTML msgs.
54 "Every nonfree program has a lord, a master --
55 and if you use the program, he is your master." Richard Stallman

Replies

Subject Author
Re: [gentoo-amd64] Re: Hard drive (installation) Rich Freeman <rich0@g.o>