Determining Which Is The Primary USB Port.

[Poster Matt]

Sorry if this is OT, I've had no luck getting this question answered
elsewhere (on web forums) and these groups tend to be populated by
people who have a higher degree of technical expertise.

Hi,

I've just got a new Sennheiser headset microphone and a Buddy USB sound
adaptor for my speech recognition software, the combination of which is
supposed to be among the best set-ups for getting the best possible
levels of speech recognition accuracy.

I'm told the Buddy USB sound adaptor should be put in the, or one of
the, Primary USB ports - I've got 8 USB ports and can't work out which
of these are Primary USB ports. Device Manager hasn't helped me, but I'm
not exactly sure what I'm looking for.

How can I tell which is a Primary USB Port, and specifically if my Buddy
USB sound adaptor is plugged into a Primary USB Port?

Thanks guys.

 

[Paul]

Sorry if this is OT, I've had no luck getting this question answered
elsewhere (on web forums) and these groups tend to be populated by
people who have a higher degree of technical expertise.

Hi,

I've just got a new Sennheiser headset microphone and a Buddy USB sound
adaptor for my speech recognition software, the combination of which is
supposed to be among the best set-ups for getting the best possible
levels of speech recognition accuracy.

I'm told the Buddy USB sound adaptor should be put in the, or one of
the, Primary USB ports - I've got 8 USB ports and can't work out which
of these are Primary USB ports. Device Manager hasn't helped me, but I'm
not exactly sure what I'm looking for.

How can I tell which is a Primary USB Port, and specifically if my Buddy
USB sound adaptor is plugged into a Primary USB Port?

Thanks guys.

In the world of USB, there are no "second class citizens"

You can have more than one controller chip, which controls USB ports.

USB USB
chip chip
/ | | \ / \
/ | | \ / \

In Device Manager, you aren't looking at physical ports, but at the logic
blocks that control the USB ports. So don't be concerned, if you have
eight physical USB ports, and only five things show up in Device Manager.
Those five things are the logic blocks that control the eight ports.
There will be more USB 1.1 logic blocks, than USB 2.0 logic blocks, and
the logic blocks are bound dynamically to the physical ports, as a function
of the device type (i.e. a USB 1.1 peripheral or a USB 2.0 peripheral).

In terms of electrical qualities, the ports on the back of the computer,
in the I/O area (that metal plate with all the connectors on it), are the
best connectors. Some DIY computer builds, have poor quality wiring to
the front mounted ports, and sometimes the front ports suffer from problems
as a result. So start your testing, using the ports on the back of the computer,
to get a good idea of how the stuff should be working.

That is as close to "Primary" as I can get for you, because the USB ports
don't have artificial titles.

If you later switch to the front mounted ports, and experience problems,
while the back ports did not give you problems, then you'll have a better
idea as to where you should be connecting.

Paul

 

[John Doe]

I've just got a new Sennheiser headset microphone and a Buddy USB
sound adaptor for my speech recognition software, the combination
of which is supposed to be among the best set-ups for getting the
best possible levels of speech recognition accuracy.

I'm hooked on speech recognition, to replace typing and to greatly
improve Windows scripting/macroing by voice activation.

Besides training your voice, the most important component is that
you use NaturallySpeaking, IMO, it's the best speech recognition for
personal computing.

I use an ordinary inexpensive USB microphone, modified to remove
most of the analog wire.

For what it's worth.
I used a digital recorder for a year or two, making notes and then
playing them back to help train my voice. Digital recorders are very
useful for a to-do list and a to-buy list, anyway. So whenever
you record a message, you just press play, then you can hear how
clear it is (or isn't). Olympus has made excellent digital recorders
IMO. Would be better if erasing a message required only two button
presses instead of three.

I'm told the Buddy USB sound adaptor should be put in the, or one
of the, Primary USB ports

I don't understand that. Digitally speaking, I can't imagine that it
would make any difference. What's left is the power supply. But if
the device you're talking about uses so much power that it requires
a particular USB port that sources the most current (at USB
voltage), sounds like it's poorly designed.

You might be getting hocus-pocus diversionary answers. Some speech
recognition spammers won't tell you that your voice is the most
critical component until after they've sold you every bit of related
hardware they can.

Good luck.

 

[Poster Matt]

In the world of USB, there are no "second class citizens"

You can have more than one controller chip, which controls USB ports.

USB USB
chip chip
/ | | \ / \
/ | | \ / \

In Device Manager, you aren't looking at physical ports, but at the logic
blocks that control the USB ports. So don't be concerned, if you have
eight physical USB ports, and only five things show up in Device Manager.
Those five things are the logic blocks that control the eight ports.
There will be more USB 1.1 logic blocks, than USB 2.0 logic blocks, and
the logic blocks are bound dynamically to the physical ports, as a function
of the device type (i.e. a USB 1.1 peripheral or a USB 2.0 peripheral).

In terms of electrical qualities, the ports on the back of the computer,
in the I/O area (that metal plate with all the connectors on it), are the
best connectors. Some DIY computer builds, have poor quality wiring to
the front mounted ports, and sometimes the front ports suffer from problems
as a result. So start your testing, using the ports on the back of the
computer, to get a good idea of how the stuff should be working.

That is as close to "Primary" as I can get for you, because the USB ports
don't have artificial titles.

If you later switch to the front mounted ports, and experience problems,
while the back ports did not give you problems, then you'll have a better
idea as to where you should be connecting.

What I have gleaned from reading various faqs and threads is that
interference from other electronics affects the audio quality. My goal
is to get up to 99% accuracy from the speech recognition software, I
already have a high level of accuracy, I just want to get up as high as
possible which people say is currently (with today's technology) about
99%. Just a little electronic interference brings that down a little. So
the advise is not to use an internal soundcard because that can be
housed near electronics which can interfere a little. So you use an
(external) USB sound card and make sure that other USB devices don't
interfere at all by making sure that the USB port is a 'Primary' one and
is directly connected to the motherboard. If there is no distinction
between 'Primary' and 'Secondary' in the USB standard might it be what
is meant is as simple as the wiring passing through several USB ports on
the way to the motherboard (and that this is to be avoided)?

I was hoping to find a quick and easy way to identify which was the
'Primary' port without running a sound test -which the software has
available- for each USB port until I find the lowest interference level.
But from what you say I think that's what needs to be done, try each
port and run a sound test and measure it's levels and final score.
Tedious with 8 ports. Still it's Sunday tomorrow, I can spare an hour or
two.

Thanks very much.

 

[John Doe]

If there is no distinction between 'Primary' and 'Secondary' in
the USB standard might it be what is meant is as simple as the
wiring passing through several USB ports on the way to the
motherboard (and that this is to be avoided)?

The wiring passes through several USB ports on the way to the
motherboard?

If you can't dazzle them with brilliance, baffle them with bullshit?

 

[Poster Matt]

I'm hooked on speech recognition, to replace typing and to greatly
improve Windows scripting/macroing by voice activation.

Besides training your voice, the most important component is that
you use NaturallySpeaking, IMO, it's the best speech recognition for
personal computing.

I could not agree more. I've been using speech recognition for a while
now and the key to high levels of accuracy is the clarity and
consistency of your pronunciation - and to be using the best software
which is, of course, NaturallySpeaking.

My accuracy levels are already very high, and my dictation voice is well
trained. Now my goal is to go that extra bit to achieve 99% accuracy.
The research I did led me to several highly rated microphones with
really good noise cancellation. The combination of the Sennheiser
microphone and a good external USB sound adaptor is recommended by users
and professionals alike and that's what I opted for.

I use an ordinary inexpensive USB microphone, modified to remove
most of the analog wire.

For what it's worth.
I used a digital recorder for a year or two, making notes and then
playing them back to help train my voice. Digital recorders are very
useful for a to-do list and a to-buy list, anyway. So whenever
you record a message, you just press play, then you can hear how
clear it is (or isn't). Olympus has made excellent digital recorders
IMO. Would be better if erasing a message required only two button
presses instead of three.

Thanks for the info.

I don't understand that. Digitally speaking, I can't imagine that it
would make any difference. What's left is the power supply. But if
the device you're talking about uses so much power that it requires
a particular USB port that sources the most current (at USB
voltage), sounds like it's poorly designed.

You might be getting hocus-pocus diversionary answers. Some speech
recognition spammers won't tell you that your voice is the most
critical component until after they've sold you every bit of related
hardware they can.

I'm sure it's not a power issue. Please see my reply to Paul when I made
my best guess as to what is meant by a 'Primary' USB port. Paul says
there's no such distinction in USB, so I've made an educated guess as to
what it's all about.

Any random readers... You really can now get awesome speeds with speech
recognition now. Even if you touch type well, you can get very
significant increases in text entry speeds. My own levels have gone
through the roof and my text entry bottleneck is now deciding what I
want to write not my typing speed.

Thanks and regards.

 

[Poster Matt]

The wiring passes through several USB ports on the way to the
motherboard?

If you can't dazzle them with brilliance, baffle them with bullshit?

I'm not an electrical engineer and have no experience of how computer
components can individually affect each other inside a PC. I was trying
to come up with a logical reason why a signal from one USB port might
degrade a little while that not happening from another port a cm or 2 or
3 away. It wasn't a statement, but a question, starting with 'might it
be' and ending with a question mark - there's no need to be dismissively
rude about out it.

I don't believe the advise given to me about performance levels being
affected by which USB port used was made up. It was given to me by a
speech recognition professional who sold me the equipment. He'd made the
sale so it wasn't sales waffle, he followed it up later with the USB
port advise, I'm sure to be genuinely helpful. But he couldn't tell me
how to determine which was, what he called, a Primary USB port beyond
trial and error. I saw the same advise in a thread on a web speech
recognition forum, but got no joy as to how to tell which a 'Primary'
USB port was from the OS of the PC. I thought the techies here in
homebuild and WinXP support groups, who have been most helpful in the
past, might be able to explain. I'm sorry if my technical competence in
this field wasn't up to making a more plausible explanation but it
doesn't sound all that stupid to me. There are physical wires, they do
carry signals, such signals can interfere with each other. I've never
wired up USB devices to connect to a motherboard but it doesn't seem out
of the question that the wires pass through other ports (obviously not
the input/output terminals). Perhaps since I've failed to dazzle you
with my 'bullshit' you can come up with a better suggestion?

Regards, matt

 

[John Doe]

....

components can individually affect each other inside a PC. I was
trying to come up with a logical reason why a signal from one USB
port might degrade a little while that not happening from another
port a cm or 2 or 3 away.

Who says it does? You?

It wasn't a statement, but a question, starting with 'might it be'
and ending with a question mark - there's no need to be
dismissively rude about out it.

I thought the techies here in homebuild and WinXP support groups,
who have been most helpful in the past, might be able to explain.

You have been helped, you just insist the help isn't good enough.

There are physical wires, they do carry signals, such signals can
interfere with each other.

Where is the question mark after that nonsense, maroon?

 

[RobV]

I'm not an electrical engineer and have no experience of how computer
components can individually affect each other inside a PC. I was
trying to come up with a logical reason why a signal from one USB
port might degrade a little while that not happening from another
port a cm or 2 or 3 away. It wasn't a statement, but a question,
starting with 'might it be' and ending with a question mark - there's
no need to be dismissively rude about out it.

I don't believe the advise given to me about performance levels being
affected by which USB port used was made up. It was given to me by a
speech recognition professional who sold me the equipment. He'd made
the sale so it wasn't sales waffle, he followed it up later with the
USB port advise, I'm sure to be genuinely helpful. But he couldn't
tell me how to determine which was, what he called, a Primary USB
port beyond trial and error. I saw the same advise in a thread on a
web speech recognition forum, but got no joy as to how to tell which
a 'Primary' USB port was from the OS of the PC. I thought the techies
here in homebuild and WinXP support groups, who have been most
helpful in the past, might be able to explain. I'm sorry if my
technical competence in this field wasn't up to making a more
plausible explanation but it doesn't sound all that stupid to me.
There are physical wires, they do carry signals, such signals can
interfere with each other. I've never wired up USB devices to connect
to a motherboard but it doesn't seem out of the question that the
wires pass through other ports (obviously not the input/output
terminals). Perhaps since I've failed to dazzle you with my
'bullshit' you can come up with a better suggestion?
Regards, matt

Don't pay any attention to him, Matt. He likes to insult people and be
a general PITA, as I've found out in the past. I only know who it is
because you included his post in your reply, as I've kill filed him long
ago and suggest you do the same.

As to your problem, perhaps the meaning of a "primary" USB port is one
that is connected directly to the motherboard, as opposed to "secondary"
ports that are on the front of the case, or located in a card slot at
the back and are connected to the motherboard by a length of cable.

The USB ports attached directly to the motherboard are those at the back
of the computer, in close proximity to the keyboard and mouse inputs,
along with any network, or serial or parallel ports (if the system has
any) and audio inputs/outputs (if the MB has integrated audio). There
are usually at least two ports in very close proximity to each other.
My particular MB has two "stacks" of two ports which are soldered
directly to the MB in the location mentioned.

HTH

Rob

 

[Paul]

What I have gleaned from reading various faqs and threads is that
interference from other electronics affects the audio quality. My goal
is to get up to 99% accuracy from the speech recognition software, I
already have a high level of accuracy, I just want to get up as high as
possible which people say is currently (with today's technology) about
99%. Just a little electronic interference brings that down a little. So
the advise is not to use an internal soundcard because that can be
housed near electronics which can interfere a little. So you use an
(external) USB sound card and make sure that other USB devices don't
interfere at all by making sure that the USB port is a 'Primary' one and
is directly connected to the motherboard. If there is no distinction
between 'Primary' and 'Secondary' in the USB standard might it be what
is meant is as simple as the wiring passing through several USB ports on
the way to the motherboard (and that this is to be avoided)?

I was hoping to find a quick and easy way to identify which was the
'Primary' port without running a sound test -which the software has
available- for each USB port until I find the lowest interference level.
But from what you say I think that's what needs to be done, try each
port and run a sound test and measure it's levels and final score.
Tedious with 8 ports. Still it's Sunday tomorrow, I can spare an hour or
two.

Thanks very much.

There is an example of a USB audio device here. It uses isochronous
endpoints, one for transmit and one for receive, and the purpose of
those, is to guarantee bandwidth and low latency for the sampling
process. (The USB20.pdf 650 page standard, from usb.org, has more
details on this.)

http://www.cmedia.com.tw/files/doc/USB/CM108 DataSheet v1.6.pdf

Any analog to digital conversion process, has the opportunity to add
background noise to the signal. And that wouldn't change, whether a regular PCI
sound card was used, or a USB audio solution was used. You would need to
check the quotations of noise floor, to see if there was a significant
difference between the various sound input solutions.

I know that it is possible for the position or shielding of a sound
card, to make a difference to audio performance. A poster here, a few
years back, mentioned doing an experiment, where he moved a sound
card to the last slot, and put a metal cover over it. He got something
like a 10dB improvement in the noise floor. And that would be caused by
reducing electromagnetic interference coming from the rest of the
computer, to the ADC.

Those are the kinds of effects that would be harder to predict (there is
no way to know how good or diligent, the designer of the USB microphone
is). As an example, there have been motherboards, where the built-in sound
was a disaster, and implies no one bothered to verify the audio performance
before the motherboard was put into production.

But as far as the USB transfer protocol goes, about the only thing
that can go wrong, is for packets to be corrupted in transit. Reading
the USB20 spec, it mentions that isochronous transfers don't have
provisions for error detection and retransmission (which might be used
for normal asynchronous transfers to peripherals). So if a packet has
bad data in it (would sound like a burst of static perhaps), USB doesn't
have a provision to fix it. This is similar to some other media, that
have no opportunity to correct errored bits. (The DVI interface to an
LCD monitor would be an example - if the signal on the cable is weak,
snow shows up, and the interface is not designed to ask for a
retransmission of any corrupted parts of the image, because the
interface is unidirectional.)

I think, by all means now, you should carry out your test cases, to
see if there is any effect. But you should be careful in your test
design, to come up with a way to measure the differences, if they
exist. I would think the design of the microphone itself, may be
more significant than the rest of the transfer process.

Paul

 

[It's Me]

As Paul mentioned, any of the motherboard mounted USB2 ports
should be equally good. With some caveats.

Exept that's not true, even in my limited experience.

I have quite often run across a PC or laptop with two USB ports on the
back. Plugging the mouse into one works, but plugging the mouse into
the other refuses to work. Anything else I've tried plugged into the
second port works. Whether this is a power issue or a Windows software
issue or something else, it definitely proves that not all USB ports
are created equal in every way.
_-_
It's Me /o o\
Over Here < U >
\ v /
/ \

 

[Franc Zabkar]

Sorry if this is OT, I've had no luck getting this question answered
elsewhere (on web forums) and these groups tend to be populated by
people who have a higher degree of technical expertise.

Hi,

I've just got a new Sennheiser headset microphone and a Buddy USB sound
adaptor for my speech recognition software, the combination of which is
supposed to be among the best set-ups for getting the best possible
levels of speech recognition accuracy.

I'm told the Buddy USB sound adaptor should be put in the, or one of
the, Primary USB ports - I've got 8 USB ports and can't work out which
of these are Primary USB ports. Device Manager hasn't helped me, but I'm
not exactly sure what I'm looking for.

How can I tell which is a Primary USB Port, and specifically if my Buddy
USB sound adaptor is plugged into a Primary USB Port?

Thanks guys.

You can use Microsoft's UVCview utility to show you how your 8 ports
and devices connect to your USB root hubs:

http://www.users.on.net/~fzabkar/USB_IDs/UVCView.x86.exe

I'm not sure how critical a consideration bandwidth would be for an
audio application, but you could try to arrange your devices so that
your microphone is the only device on a particular hub.

- Franc Zabkar

 

[M.I.5¾]

Sorry if this is OT, I've had no luck getting this question answered
elsewhere (on web forums) and these groups tend to be populated by people
who have a higher degree of technical expertise.

Hi,

I've just got a new Sennheiser headset microphone and a Buddy USB sound
adaptor for my speech recognition software, the combination of which is
supposed to be among the best set-ups for getting the best possible levels
of speech recognition accuracy.

I'm told the Buddy USB sound adaptor should be put in the, or one of the,
Primary USB ports - I've got 8 USB ports and can't work out which of these
are Primary USB ports. Device Manager hasn't helped me, but I'm not
exactly sure what I'm looking for.

How can I tell which is a Primary USB Port, and specifically if my Buddy
USB sound adaptor is plugged into a Primary USB Port?

Audio devices of this type operate using USB1 communication but using a
special mode known as isochronous mode. There have been many issues with
this mode where there are several USB devices on the system. Basically for
the most reliable operation, the device need to be connected to a root port.
That is: a port that connected directly to the root hub in the motherboard's
southbridge chip (any port mounted directly on the motherboard should be
such a port. The problem arises when the device is connected via a hub
where the hub's own communications plus te communication of other devices
connected to the hub disrupt your audio communication. It shouldn't happen
but it does.

 

[Poster Matt]

You can use Microsoft's UVCview utility to show you how your 8 ports
and devices connect to your USB root hubs:

http://www.users.on.net/~fzabkar/USB_IDs/UVCView.x86.exe

I'm not sure how critical a consideration bandwidth would be for an
audio application, but you could try to arrange your devices so that
your microphone is the only device on a particular hub.

Thanks Franc. I'll take a look. Cheers for the file link.

Regards, etc..

 

[Andrew Smallshaw]

I'm not sure how critical a consideration bandwidth would be for an
audio application, but you could try to arrange your devices so that
your microphone is the only device on a particular hub.

I had exactly the same thoughts. The only rational reasons I can
see for demanding a root hub is if there is any concern about
latency - but if that is the case then recommending USB in the
first place is ridiculous since it is something that USB does poorly
at the best of times.

Reading through the OP's requirements I can't help thinking that
they have been attacked by a marketroid somewhere along the line.
Speech recognition should need a decent mic and that is about it.
I suspect that if the software really requests all this it is simply
an attempt to pass off poor product performance onto the hardware.

In any case you may find that you don't have any root hubs that
you can connect to. It is not unusual for the USB bus to be broken
up by a hub either onboard or integrated into the USB chipset
itself. In such circumstances there may be no socket that connects
directly to the root hub.

 

[Paul]

I had exactly the same thoughts. The only rational reasons I can
see for demanding a root hub is if there is any concern about
latency - but if that is the case then recommending USB in the
first place is ridiculous since it is something that USB does poorly
at the best of times.

Reading through the OP's requirements I can't help thinking that
they have been attacked by a marketroid somewhere along the line.
Speech recognition should need a decent mic and that is about it.
I suspect that if the software really requests all this it is simply
an attempt to pass off poor product performance onto the hardware.

In any case you may find that you don't have any root hubs that
you can connect to. It is not unusual for the USB bus to be broken
up by a hub either onboard or integrated into the USB chipset
itself. In such circumstances there may be no socket that connects
directly to the root hub.

USB has isochronous capability, for reserving bandwidth for things
like audio applications. That means continuous bit rate applications
were not an afterthought.

This USB audio chip, has an isochronous block for input and one
for output.

http://www.cmedia.com.tw/files/doc/USB/CM108 DataSheet v1.6.pdf

This article summarizes the characteristics.

http://www.beyondlogic.org/usbnutshell/usb4.htm

"Isochronous Transfers provide

* Guaranteed access to USB bandwidth.
* Bounded latency."

HTH,
Paul

 

[Franc Zabkar]

USB has isochronous capability, for reserving bandwidth for things
like audio applications. That means continuous bit rate applications
were not an afterthought.

This USB audio chip, has an isochronous block for input and one
for output.

http://www.cmedia.com.tw/files/doc/USB/CM108 DataSheet v1.6.pdf

This article summarizes the characteristics.

http://www.beyondlogic.org/usbnutshell/usb4.htm

"Isochronous Transfers provide

* Guaranteed access to USB bandwidth.
* Bounded latency."

HTH,
Paul

Thanks.

FWIW, here is how UVCview sees my USB VoIP phone:
http://www.users.on.net/~fzabkar/USB_IDs/freshtel.txt

There are two references (IN/OUT) to an "Isochronous Transfer Type".
The sample rate is 8000Hz.

This *may* be the actual phone:
http://www.yealink.com/en/view.asp?ClassLayer=10

- Franc Zabkar

 

[Andrew Smallshaw]

USB has isochronous capability, for reserving bandwidth for things
like audio applications. That means continuous bit rate applications
were not an afterthought.

I am more than familar with USB's different transfer modes, you
don't need to start quoting web sites in that regard. However,
don't confuse bounded latency with _low_ latency - it is still
quite high by historical standards. You won't get a lantency of
less than 1 or 2 ms using USB even directly connected to the root
hub - this may go up to perhaps 10 ms if it is going through a
couple of hubs first. If you think this doesn't sound too bad
consider that good ol' RS232 allowed responses within a couple of
_microseconds_.

 

[Paul]

I am more than familar with USB's different transfer modes, you
don't need to start quoting web sites in that regard. However,
don't confuse bounded latency with _low_ latency - it is still
quite high by historical standards. You won't get a lantency of
less than 1 or 2 ms using USB even directly connected to the root
hub - this may go up to perhaps 10 ms if it is going through a
couple of hubs first. If you think this doesn't sound too bad
consider that good ol' RS232 allowed responses within a couple of
_microseconds_.

The info was more for the benefit of the OP, who appears spooked
by USB.

Paul