Gentoo Archives: gentoo-user

From: walt <w41ter@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: [OT] Disappointing USB3 performance
Date: Mon, 24 Oct 2011 23:20:21
Message-Id: j84rob$50r$
In Reply to: [gentoo-user] [OT] Disappointing USB3 performance by walt
1 On 10/24/2011 10:28 AM, walt wrote:
2 > ...
3 > Over at least six trials on each docking station I consistently
4 > get 105 seconds for USB and 84 seconds for e-sata, a 5:4 ratio
5 > in favor of e-sata/sata over USB3/sata...
7 Wow, lots of great answers, guys, thanks. Enough material to give
8 me lots more questions to ask you :)
10 Like, for example, in theory the raw bit-rate for USB3 is more than
11 enough to keep up with any existing consumer hard drive, right? The
12 speed of usb/sata protocol translation should be very fast compared
13 to the speed of a spinning mechanical disk (I think?)
15 Now, lack of DMA is another story for hard disks, certainly. Here's
16 where my ignorance of hardware limits my thinking:
18 AFAIK the device driver *always* sits between the disk drive and the
19 DMA hardware, doesn't it?
21 Seems to me that the USB3 driver should be fast enough to shuttle the
22 raw disk data (somehow) to the DMA hardware just like the pata/sata
23 drivers do. It's that "somehow" that I obviously don't understand.
25 Where am I thinking wrong about the problem?


Subject Author
Re: [gentoo-user] Re: [OT] Disappointing USB3 performance Michael Mol <mikemol@×××××.com>