USB 2.0 Speed

  • Thread starter Thread starter mcp6453
  • Start date Start date
M

mcp6453

I just added an external USB hard drive to my Windows 2000 SP4 computer.
The transfers over the USB port seem to be taking forever (over 3 hours
for 10 GB.) How can I test to prove that the port is operating at 2.0
instead of 1.1? I saw a tech note recently that pointed to a software or
driver change that may be necessary, but I didn't save it, and I don't
remember where I saw it. The computer is an IBM Netvista.
 
mcp6453 said:
I just added an external USB hard drive to my Windows 2000 SP4 computer.
The transfers over the USB port seem to be taking forever (over 3 hours
for 10 GB.) How can I test to prove that the port is operating at 2.0
instead of 1.1? I saw a tech note recently that pointed to a software or
driver change that may be necessary, but I didn't save it, and I don't
remember where I saw it. The computer is an IBM Netvista.
Click to expand...

IBM web site says it's 1.1.
 
USB devices are multi speed interfaces.

USB 1.1 supports 1.5 Mb and 11mb.

USB 2.0 also add support of 480Mb.

All devices must be at least USB 1.0 compliant, what means, use LVD signals, and
support 1.5 and 11 Mb speeds.

As answer to your problem, just try to understand that YOU as user are responsible
to check if all devices in a serie are USB 2.0 compliant.

I really meant serie, and not chain nor tree !!!

That means, your host, and hubs MUST be 2.0 : there MUST be a 'very high speed' way
from your processor to your drive if you want it fast.

The tree can have a high speed (11), or low speed (1.5) branch (USB 1.1 hub, USB
mouse ...), that will affect the disk speed (for tree shape reason), but only by 2
to 10% (thus not really visible for the user).

I now tend to use two trees on some computers: two different root concentrators: one
1.1 for low and high speed devices that expect low latency (mouse, joystick, IR),
and a very high speed for storage. Avoids slow mouse on file transferts with poor
systems (P3 500), or slow transferts while trying to work precise input (Wacom like
tables).

All cables shall be compliant. If you ever find an old cable provided with USB 1.1
device, and that putting this cable between the USB2 disk and the host slows down
speed of disk (or entire tree), then you can start a law suit against manifacturer
of cable. USB 1.1 MUST be very high speed compliant.

USB 1.0 cables seems not to stand that upward compatibility. I may remember bad.

Avoid any kind of adaptors. If required, buy new wires with apropriate plugs.
 
DEMAINE Benoit-Pierre said:
USB 1.1 supports 1.5 Mb and 11mb.

USB 2.0 also add support of 480Mb. ....
2.0 : there MUST be a 'very high speed' ....
high speed (11), or low speed (1.5)
Click to expand...

Just to avoid confusion, the usual names for these speeds are:

480Mbps: hi speed (fastest USB 2.0 speed)
12Mbps: full speed (fastest USB 1.1 speed)

(These names do not appear very logical, but I guess full speed means
full USB 1.1 speed).

- anton
 
Just to avoid confusion, the usual names for these speeds are:
480Mbps: hi speed (fastest USB 2.0 speed)
12Mbps: full speed (fastest USB 1.1 speed)

(These names do not appear very logical, but I guess full speed means
full USB 1.1 speed).
Click to expand...

you are 100% right. I mixed up full speed and high speed.

Hopefully, by old times, full speed described the highest speed they could conceive
by that time. 100y ago, nobody would believe we would have a trip on moon so fast.

***

/me cries when he sees in shops 802.3 NICs full duplex 100mb to be labelled 200mb ...

/me also cries when people claim FireWire 400Mb to be slower than USB 2.0. USB is
forver half duplex. Fire Wire is full duplex.

And I am sorry to have to conclude:
400 fd > 480 hd
 
I don't know of a way to test it with software (though there may be
one), so I stick into the port an Attache 2.0 thumb drive. If put into
a USB 1.1 port, it complains that it is in a slow port and suggests
that you find a faster one. If it does not complain, it is USB 2. That
is how I test. Not very elegant but it works.

Irwin
 
I don't know of a way to test it with software (though there may be
one), so I stick into the port an Attache 2.0 thumb drive. If put into
a USB 1.1 port, it complains that it is in a slow port and suggests
that you find a faster one. If it does not complain, it is USB 2. That
is how I test. Not very elegant but it works.

Irwin
Click to expand...

IRC for Windows XP only.
 
Back
Top