More on USB2

  • Thread starter Thread starter gecko
  • Start date Start date
G

gecko

Help me understand what is going on. Please.

I have two machines:
Machine A has a total of six USB ports (connectors)
Machine B has a total of eight USB ports (connectors)

I ran EVEREST on both to try to see if either machine truly had USB2.

Everest shows 4 USB1 Controllers and 1 USB2 Controller on BOTH
MACHINES!

So I presume that I indeed do have USB2 capability on both machines.
But which port (or ports)? And why 5 controllers for 6 (or 8) ports?

Am I confused? You betcha.

TIA

G
 
Unfortunately what you've observed is way too common.
manufacturer's having both USB1 and USB 2 ports.

Unless you can find the manual for the machine that describes which port it
which...
you will have to use a little trial and error to determine which is which

(you can watch the data transfer rate from an external USB device)

I usually just put a piece of tape over the USB1 ports once I locate them...
though they would be fine for a USB keyboard or mouse
Click to expand...

I hope you're kidding...........

G
 
gecko said:
Help me understand what is going on. Please.

I have two machines:
Machine A has a total of six USB ports (connectors)
Machine B has a total of eight USB ports (connectors)

I ran EVEREST on both to try to see if either machine truly had USB2.

Everest shows 4 USB1 Controllers and 1 USB2 Controller on BOTH
MACHINES!

So I presume that I indeed do have USB2 capability on both machines.
But which port (or ports)? And why 5 controllers for 6 (or 8) ports?

Am I confused? You betcha.
Click to expand...


Unfortunately what you've observed is way too common.
manufacturer's having both USB1 and USB 2 ports.

Unless you can find the manual for the machine that describes which port it
which...
you will have to use a little trial and error to determine which is which

(you can watch the data transfer rate from an external USB device)

I usually just put a piece of tape over the USB1 ports once I locate them...
though they would be fine for a USB keyboard or mouse
 
gecko said:
I hope you're kidding...........

G
Click to expand...

No I'm not USB1 is just fine for keyboards or mice...
but most other devices I'd be sure to use USB2 especially data devices!
 
Help me understand what is going on. Please.

I have two machines:
Machine A has a total of six USB ports (connectors)
Machine B has a total of eight USB ports (connectors)

I ran EVEREST on both to try to see if either machine truly had USB2.

Everest shows 4 USB1 Controllers and 1 USB2 Controller on BOTH
MACHINES!

So I presume that I indeed do have USB2 capability on both machines.
But which port (or ports)? And why 5 controllers for 6 (or 8) ports?

Am I confused? You betcha.

TIA
Click to expand...

Get the make and model number info, go to the respective
manufacturer's website and get the specs for the board.
Otherwise note which chipset (southbridge, if it has one)
and Google for the USB support that chipset offers. If some
of the ports are supported by a 2nd discrete controller chip
in addition to the motherboard chipset, Google for the
control part # to find USB version support.

Most likely, all ports on both boards are USB2.
 
No I'm not USB1 is just fine for keyboards or mice...
but most other devices I'd be sure to use USB2 especially data devices!
Click to expand...

Which is exactly why I need to know.

Thanks
G
 
Get the make and model number info, go to the respective
manufacturer's website and get the specs for the board.
Otherwise note which chipset (southbridge, if it has one)
and Google for the USB support that chipset offers. If some
of the ports are supported by a 2nd discrete controller chip
in addition to the motherboard chipset, Google for the
control part # to find USB version support.

Most likely, all ports on both boards are USB2.
Click to expand...

Thanks

But why the disparity between the number of Controllers in Device
Manager and the number of USB ports available in the tower?

G
 
gecko said:
Help me understand what is going on. Please.

I have two machines:
Machine A has a total of six USB ports (connectors)
Machine B has a total of eight USB ports (connectors)

I ran EVEREST on both to try to see if either machine truly had USB2.

Everest shows 4 USB1 Controllers and 1 USB2 Controller on BOTH
MACHINES!

So I presume that I indeed do have USB2 capability on both machines.
But which port (or ports)? And why 5 controllers for 6 (or 8) ports?

Am I confused? You betcha.

TIA

G
Click to expand...

The items shown in Device Manager are not "Ports".
They are logic blocks. They are dynamically connected
to the Ports, as required. In other words, during
negotiation, a Port can be run in USB 1.1 or USB 2.0
mode, so the wiring to the logic block has to change
on the fly.

Try Figure 25 on page 223 of this document. This is easier
than me trying to draw this in ASCII art.

http://download.intel.com/design/chipsets/datashts/25251601.pdf

One USB 1.1 logic block, is used on a maximum of two USB ports.
The USB 2.0 logic block, is used by up to eight ports.

This tool can give some info on speeds, but the tool won't
explain why a device is not running at the maximum it supports.

"UVCView – Diagnostic Tool for USB Video Class Hardware"
http://www.microsoft.com/whdc/device/stream/vidcap/UVCViewdwn.mspx

For a USB device, the "Current Config" value tells you what
speed the device is currently running at.

Current Config Value: 0x01 -> Device Bus Speed: Full (i.e. USB 1.1)

The "bcdUSB" tells you what standards the plugged in device claims
to support. This is basically a declaration of their max possible
speed, in a sense. So "Current Config" cannot be greater than "bcdUSB".

Values: 0100, 0110, and 0200, for USB 1.0, USB 1.1, and USB 2.0 standards.
Example:

bcdUSB: 0x0110

Reference - http://www.beyondlogic.org/usbnutshell/usb5.htm

What is still missing, is any info about why a device won't run at
the full speed. I.e. If "Current Config" is less than bcdUSB, and
yet there is an "Enhanced" section (USB2 capable logic block) showing
in UVCView, it doesn't explain why the driver is not moving the device
to the USB2 section.

At least in some cases, this can be explained by poor signal quality
on the computer case front USB ports. Signal quality is generally
excellent on the motherboard rear USB Ports, as the signals there
travel on the PCB - the engineer who designs the board is careful
to set the impedance correctly for such signals. But the computer
case wiring is done by careless people, which is why some of it
is busted with respect to USB2 operation. Antec was noted for this,
but has finally fixed it after a couple years of customer complaints.

Paul
 
Somewhere on the interweb "gecko" typed:
Which is exactly why I need to know.

Thanks
G
Click to expand...

See Paul's reply. The others were all pretty much blowing smoke. That's not
to say that, on some mobos, some ports just won't work as they're supposed
to (at USB2 speed). The only way to find out is to try. Slam a USB stick in
and see if XP tells you that it needs a faster port. If it doesn't chances
are it's working fine at USB2 speed.
 
Help me understand what is going on. Please.

I have two machines:
Machine A has a total of six USB ports (connectors)
Machine B has a total of eight USB ports (connectors)

I ran EVEREST on both to try to see if either machine truly had USB2.

Everest shows 4 USB1 Controllers and 1 USB2 Controller on BOTH
MACHINES!

So I presume that I indeed do have USB2 capability on both machines.
But which port (or ports)? And why 5 controllers for 6 (or 8) ports?

Am I confused? You betcha.

TIA

G
Click to expand...
My Dell 8300 has eight ports (plugins).
All tests show that it has four USB1 hubs with 2 ports each.
Also shows an "Enhanced" (hence USB2) hub with eight ports.
Windows enumerator interrogates the devices and assigns them to the
appropriate port. Thus any one of the jacks can be either USB type!
Sometimes the decision is wrong, I know not why, and disconnecting and
reconnecting the device usually fixes it. This rarely happens on
startup or restart, but fairly often on returning from Standby.
The USB Device viewer can be revealing.
 
But why the disparity between the number of Controllers in Device
Manager and the number of USB ports available in the tower?

G
Click to expand...


Just because you have a chip that can do XYZ, it doesn't
mean the motherboard manufacturer implemented all the ports
or in some cases, the ports "could" work but there are or
aren't additional USB pin headers you would need to connect
USB port-dongles to in order to use them.
 
The items shown in Device Manager are not "Ports".
They are logic blocks. They are dynamically connected
to the Ports, as required. In other words, during
negotiation, a Port can be run in USB 1.1 or USB 2.0
mode, so the wiring to the logic block has to change
on the fly.

Try Figure 25 on page 223 of this document. This is easier
than me trying to draw this in ASCII art.

http://download.intel.com/design/chipsets/datashts/25251601.pdf

One USB 1.1 logic block, is used on a maximum of two USB ports.
The USB 2.0 logic block, is used by up to eight ports.

This tool can give some info on speeds, but the tool won't
explain why a device is not running at the maximum it supports.

"UVCView – Diagnostic Tool for USB Video Class Hardware"
http://www.microsoft.com/whdc/device/stream/vidcap/UVCViewdwn.mspx

For a USB device, the "Current Config" value tells you what
speed the device is currently running at.

Current Config Value: 0x01 -> Device Bus Speed: Full (i.e. USB 1.1)

The "bcdUSB" tells you what standards the plugged in device claims
to support. This is basically a declaration of their max possible
speed, in a sense. So "Current Config" cannot be greater than "bcdUSB".

Values: 0100, 0110, and 0200, for USB 1.0, USB 1.1, and USB 2.0 standards.
Example:

bcdUSB: 0x0110

Reference - http://www.beyondlogic.org/usbnutshell/usb5.htm

What is still missing, is any info about why a device won't run at
the full speed. I.e. If "Current Config" is less than bcdUSB, and
yet there is an "Enhanced" section (USB2 capable logic block) showing
in UVCView, it doesn't explain why the driver is not moving the device
to the USB2 section.

At least in some cases, this can be explained by poor signal quality
on the computer case front USB ports. Signal quality is generally
excellent on the motherboard rear USB Ports, as the signals there
travel on the PCB - the engineer who designs the board is careful
to set the impedance correctly for such signals. But the computer
case wiring is done by careless people, which is why some of it
is busted with respect to USB2 operation. Antec was noted for this,
but has finally fixed it after a couple years of customer complaints.

Paul
Click to expand...
Thanks all

I downloaded and ran UVCView on both machines. It shows 8 ports even
though one machine only has 6. In any case, I stuck a Memory Stick
into each of the USB ports and UVCView showed it as USB-2 in all
cases. Ergo, I guess I can conclude that all of my USB ports on both
machines can handle USB2.
G
 
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