Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-10-09 Thread Lu Baolu
On 10/09/2014 07:07 PM, Mark Knibbs wrote: [For removable media, it's a good idea to disable polling for medium changes before running a test. Depending on kernel & distribution that could be achieved by doing udisks --inhibit-all-polling and/or for example echo -1 >/sys/block/sdb/even

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-10-09 Thread Alan Stern
On Thu, 9 Oct 2014, Mark Knibbs wrote: > I finally finished doing git bisect between 2.6.33 and 2.6.34. Sadly I'm > not really any the wiser, since the result looks pretty bogus. > > The supposedly-bad commit was: > 002345925e6c45861f60db6f4fc6236713fd8847 > syslog: distinguish between /proc/

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-10-09 Thread Mark Knibbs
Hi, On Thu, 09 Oct 2014 16:45:39 +0800 Lu Baolu wrote: > I got a different result with my machine. Below is the details. > ... > >>> Connected to USB 2.0 port via USB 1.1 hub: > ... > allen@allen-ivb:~$ sudo ddpt if=/dev/sg2 bs=512 bpt=240 count=65536 > verbose=2 > ... > time to read data: 30.

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-10-09 Thread Mark Knibbs
On Mon, 29 Sep 2014 09:28:37 -0400 (EDT) Alan Stern wrote: > On Sun, 28 Sep 2014, Mark Knibbs wrote: > > > > There's no telling the reason for this difference. It's got to be a > > > hardware issue, though, not a software problem. Maybe your xHCI > > > controller just isn't optimized for carry

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-10-09 Thread Lu Baolu
Hi Mark, I got a different result with my machine. Below is the details. >>> Kernel version allen@allen-ivb:~$ uname -a Linux allen-ivb 3.17.0+ #1 SMP Thu Oct 9 16:19:28 CST 2014 x86_64 x86_64 x86_64 GNU/Linux >>> Host controler information allen@allen-ivb:~$ lspci | grep USB 00:14.0 USB co

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-30 Thread Mark Knibbs
On Tue, 30 Sep 2014 14:10:28 +0800 "Lu, Baolu" wrote: > On 9/30/2014 5:03 AM, Mark Knibbs wrote: > > Great. I hope someone else is motivated to reproduce the issue. It will > > take a long time for me to bisect due to my slow computer. > Hi Mark, > > I tried to reproduce this issue. I connected

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-30 Thread Mark Knibbs
On Tue, 30 Sep 2014 14:10:28 +0800 "Lu, Baolu" wrote: > I tried to reproduce this issue. I connected a USB key under a > full-speed hub. > > sg_rbuf returns error which I am not familiar with. > > allen@allen-ivb:~$ lsusb -t > [...snip...] > /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehc

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-29 Thread Lu, Baolu
On 9/30/2014 5:03 AM, Mark Knibbs wrote: Great. I hope someone else is motivated to reproduce the issue. It will take a long time for me to bisect due to my slow computer. Hi Mark, I tried to reproduce this issue. I connected a USB key under a full-speed hub. sg_rbuf returns error which I a

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-29 Thread Mark Knibbs
On Mon, 29 Sep 2014 09:28:37 -0400 (EDT) Alan Stern wrote: > On Sun, 28 Sep 2014, Mark Knibbs wrote: > > > > There's no telling the reason for this difference. It's got to be a > > > hardware issue, though, not a software problem. Maybe your xHCI > > > controller just isn't optimized for carry

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-29 Thread Alan Stern
On Sun, 28 Sep 2014, Mark Knibbs wrote: > > There's no telling the reason for this difference. It's got to be a > > hardware issue, though, not a software problem. Maybe your xHCI > > controller just isn't optimized for carrying out full-speed transfers. > > That's a possibility, but the improv

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-28 Thread Mark Knibbs
On Thu, 25 Sep 2014 11:15:40 -0400 (EDT) Alan Stern wrote: > On Wed, 24 Sep 2014, Mark Knibbs wrote: > > > On Wed, 24 Sep 2014 11:37:11 -0400 (EDT) > > Alan Stern wrote: > > > > > On Wed, 24 Sep 2014, Mark Knibbs wrote: > > > > > > > I did some benchmarks to check the maximum transfer rate of

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-25 Thread Alan Stern
On Wed, 24 Sep 2014, Mark Knibbs wrote: > On Wed, 24 Sep 2014 11:37:11 -0400 (EDT) > Alan Stern wrote: > > > On Wed, 24 Sep 2014, Mark Knibbs wrote: > > > > > I did some benchmarks to check the maximum transfer rate of a USB-to-SCSI > > > converter. The converter is USB 1.1, so limited to the 1

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-24 Thread Mark Knibbs
On Wed, 24 Sep 2014 11:37:11 -0400 (EDT) Alan Stern wrote: > On Wed, 24 Sep 2014, Mark Knibbs wrote: > > > I did some benchmarks to check the maximum transfer rate of a USB-to-SCSI > > converter. The converter is USB 1.1, so limited to the 12Mbps full speed > > rate. The performance when connect

Re: Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-24 Thread Alan Stern
On Wed, 24 Sep 2014, Mark Knibbs wrote: > Hi, > > I did some benchmarks to check the maximum transfer rate of a USB-to-SCSI > converter. The converter is USB 1.1, so limited to the 12Mbps full speed > rate. The performance when connected to a USB 3.0 port is significantly > worse than when connec

Poor performance with USB 1.1 drive connected to USB 3.0 port

2014-09-24 Thread Mark Knibbs
Hi, I did some benchmarks to check the maximum transfer rate of a USB-to-SCSI converter. The converter is USB 1.1, so limited to the 12Mbps full speed rate. The performance when connected to a USB 3.0 port is significantly worse than when connected to a USB 2.0 port, about 26.5% slower (0.63MB/sec