Oh sorry Roy... I guess I was the only one that missed that part. Well
that part isn't good. I have a lot here to do and I will test my hub
here and see if I got that too with one 2.0 device wanting 480Mb/s and
it won't go that high. As theoretically it should be at least very close
being the only device connected to the hub.

--
Bill

Posted by BillW50 on April 16, 2008, 3:02 pm

Please log in for more thread options

M.I.5¾ typed on Tue, 15 Apr 2008 08:07:25 +0100:

>> M.I.5¾ typed on Mon, 14 Apr 2008 07:54:27 +0100:

>>>> Whoa Roy! Nobody has told you this yet and this is very important!

>>>> Here is how USB hubs work! And USB 2.0 hubs are really USB 2.0

>>>> hubs, but here is the catch.

>>>>

>>>> If you connect up any USB 1.1 device to the hub, the whole hub

>>>> drops down to 1.1 speeds. Your ports on the laptop don't act this

>>>> way, just hubs acts this way. Most keyboards and mice are USB 1.1

>>>> devices. Just something to think about.

>>>

>>> What utter rubbish.

>>>

>>> If it did, it would be a complete violation of the USB 2

>>> specification. In fact what is required is that a fully USB2

>>> compliant hub is required to upconvert any low or fast speed

>>> peripheral communication to the fast speed for onward transmission.

>>> I am not aware of any USB2 hub chipset that behaves the way you say.

>> Yeah well what can I say? I know how it is supposed to work, but it

>> doesn't appear to work that way to me. I am staring at my Cable to Go

>> Hi-Speed 4 port USB (2001 era I think) Hub and when I connect any

>> device slower other than 480Mb/s (USB 2.0) everything goes to crap

>> for bandwidth. And I will sometimes get errors stating this device

>> is connected to a slower than an USB 2.0 port. I am not alone with

>> this problem either.

> I can only suggest that something is wrong with your hub.

Nope that is the way hubs work. Single TT hubs can only allow 12Mb/s for
all 1.0 and 1.1 devices connected to it. And this takes away from your
480Mb/s total.

>> "As long as you don't mix USB 1.1 & USB 2.0 stuff on the same hub,

>> you will be fine. A simple rule is to keep all USB 1.1 to the root

>> ports, and connect all Hi-Speed to the USB 2.0 hub."

>> http://www.everythingusb.com/belkin_tunesync_for_ipod.html

> I don't know where he gets this strange idea from. I have USB1 and

> USB2 stuff connected to the same 7 port hub (and it's a Belkin), and

> I get full 480 Mbps speed out of all the USB2 devices. USB2 hubs

> actually contain duplicated ports in a similar way to each root port

> actually having two root hubs and two controllers (they can't

> possibly work any other way).

Key word is total. Yes you can get 480Mb/s total. But if each device
wants 480Mb/s per device it just isn't going to happen. Since the port
the hub is plugged into can only handle 480Mb/s max. If you got 7
devices wanting 480Mb/s at the same time, as you would be trying to push
3360Mb/s through a 480Mb/s USB 2.0 port on your laptop.

>> So how it is supposed to work vs. how it really works are two

>> different things. I don't know? Blame manufactures claiming they are

>> Hi-speed USB when they really are not. Blame single transaction

>> translator (TT) USB 2.0 hubs which can get overwelmed with 1.1

>> (12Mb/s) devices? I don't know what is the reason M.I.5¾? But I do

>> know mixing Hi-Speed (2.0) with other speeds on a Hi-Speed hub

>> usually doesn't work very well for bandwidth.

> As I said, the spec requires that USB2 (high speed) hubs upconverts

> the fast and slow devices to high speed so the impact on the

> bandwidth should be no more than the impact of adding more high

> speed devices. This came about because the impact on bandwidth of

> adding more than one or two slow devices to a pure USB1 system was

> almost intolerable. All the USB2 hubs that I am aware of behave

> according to the spec. There is a part of the spec that states that

> if you have both USB2 and USB1 hubs that the USB1 devices should be

> connected to the USB1 hub but this is is purely to avoid

> unnecessarily occupying a USB2 port (and I wonder if this is what

> that author is getting confused with). The USB1 hub can, of course,

> be plugged into a USB2 hub.

Well having many 1.1 devices on a single TT USB 2.0 hub is bad because
all 1.1 and even 1.0 devices can have only 12Mb/s total from the hub.
All 2.0 devices get the rest of the 480Mb/s. Well 468Mb/s actually in
this case. Multiple TT hubs can fix the 1.0 and 1.1 problem. But it eats
even more away from your 480Mb/s total. As each 1.0 can cost you 1.5Mb/s
and each 1.1 can cost you 12Mb/s.

--
Bill

Posted by M.I.5¾ on April 17, 2008, 3:04 am

Please log in for more thread options

> M.I.5¾ typed on Tue, 15 Apr 2008 08:07:25 +0100:

>>> M.I.5¾ typed on Mon, 14 Apr 2008 07:54:27 +0100:

>>>>> Whoa Roy! Nobody has told you this yet and this is very important!

>>>>> Here is how USB hubs work! And USB 2.0 hubs are really USB 2.0

>>>>> hubs, but here is the catch.

>>>>>

>>>>> If you connect up any USB 1.1 device to the hub, the whole hub

>>>>> drops down to 1.1 speeds. Your ports on the laptop don't act this

>>>>> way, just hubs acts this way. Most keyboards and mice are USB 1.1

>>>>> devices. Just something to think about.

>>>>

>>>> What utter rubbish.

>>>>

>>>> If it did, it would be a complete violation of the USB 2

>>>> specification. In fact what is required is that a fully USB2

>>>> compliant hub is required to upconvert any low or fast speed

>>>> peripheral communication to the fast speed for onward transmission.

>>>> I am not aware of any USB2 hub chipset that behaves the way you say.

>>>

>>> Yeah well what can I say? I know how it is supposed to work, but it

>>> doesn't appear to work that way to me. I am staring at my Cable to Go

>>> Hi-Speed 4 port USB (2001 era I think) Hub and when I connect any

>>> device slower other than 480Mb/s (USB 2.0) everything goes to crap

>>> for bandwidth. And I will sometimes get errors stating this device

>>> is connected to a slower than an USB 2.0 port. I am not alone with

>>> this problem either.

>> I can only suggest that something is wrong with your hub.

> Nope that is the way hubs work. Single TT hubs can only allow 12Mb/s for

> all 1.0 and 1.1 devices connected to it. And this takes away from your

> 480Mb/s total.

I suggest that you go and read the USB2.0 specification. Such a hub cannot
be described as USB2 compliant - and it wouldn't work anyway (see below).

>>> "As long as you don't mix USB 1.1 & USB 2.0 stuff on the same hub,

>>> you will be fine. A simple rule is to keep all USB 1.1 to the root

>>> ports, and connect all Hi-Speed to the USB 2.0 hub."

>>>

>>> http://www.everythingusb.com/belkin_tunesync_for_ipod.html

>> I don't know where he gets this strange idea from. I have USB1 and

>> USB2 stuff connected to the same 7 port hub (and it's a Belkin), and

>> I get full 480 Mbps speed out of all the USB2 devices. USB2 hubs

>> actually contain duplicated ports in a similar way to each root port

>> actually having two root hubs and two controllers (they can't

>> possibly work any other way).

> Key word is total. Yes you can get 480Mb/s total. But if each device wants

> 480Mb/s per device it just isn't going to happen. Since the port the hub

> is plugged into can only handle 480Mb/s max. If you got 7 devices wanting

> 480Mb/s at the same time, as you would be trying to push 3360Mb/s through

> a 480Mb/s USB 2.0 port on your laptop.

>>> So how it is supposed to work vs. how it really works are two

>>> different things. I don't know? Blame manufactures claiming they are

>>> Hi-speed USB when they really are not. Blame single transaction

>>> translator (TT) USB 2.0 hubs which can get overwelmed with 1.1

>>> (12Mb/s) devices? I don't know what is the reason M.I.5¾? But I do

>>> know mixing Hi-Speed (2.0) with other speeds on a Hi-Speed hub

>>> usually doesn't work very well for bandwidth.

>> As I said, the spec requires that USB2 (high speed) hubs upconverts

>> the fast and slow devices to high speed so the impact on the

>> bandwidth should be no more than the impact of adding more high

>> speed devices. This came about because the impact on bandwidth of

>> adding more than one or two slow devices to a pure USB1 system was

>> almost intolerable. All the USB2 hubs that I am aware of behave

>> according to the spec. There is a part of the spec that states that

>> if you have both USB2 and USB1 hubs that the USB1 devices should be

>> connected to the USB1 hub but this is is purely to avoid

>> unnecessarily occupying a USB2 port (and I wonder if this is what

>> that author is getting confused with). The USB1 hub can, of course,

>> be plugged into a USB2 hub.

> Well having many 1.1 devices on a single TT USB 2.0 hub is bad because all

> 1.1 and even 1.0 devices can have only 12Mb/s total from the hub. All 2.0

> devices get the rest of the 480Mb/s. Well 468Mb/s actually in this case.

> Multiple TT hubs can fix the 1.0 and 1.1 problem. But it eats even more

> away from your 480Mb/s total. As each 1.0 can cost you 1.5Mb/s and each

> 1.1 can cost you 12Mb/s.

Absolute rubbish. All slow and fast communication must be up converted to
480 Mbps for onward transmission. Read the USB2.0 spec and you will see
that this is so. A hub operating as you describe cannot be described as
USB2.0 compliant, and wouldn't work with fast and slow signals. Even if you
connect a USB1.0 compliant hub to a USB2.0 hub, although the USB1 hub does
not convert, the USB2 hub must upconvert all the communication. Since the
USB2 hub is ultimately connected to the enhanced host port, this must be so
as the enhanced port is unable to handle fast or slow communication (the
port required to do so is technically very different).

Posted by BillW50 on April 17, 2008, 7:32 am

Please log in for more thread options

M.I.5¾ typed on Thu, 17 Apr 2008 08:04:29 +0100:

>> M.I.5¾ typed on Tue, 15 Apr 2008 08:07:25 +0100:

>>>> M.I.5¾ typed on Mon, 14 Apr 2008 07:54:27 +0100:

>>>>>> Whoa Roy! Nobody has told you this yet and this is very

>>>>>> important! Here is how USB hubs work! And USB 2.0 hubs are

>>>>>> really USB 2.0 hubs, but here is the catch.

>>>>>>

>>>>>> If you connect up any USB 1.1 device to the hub, the whole hub

>>>>>> drops down to 1.1 speeds. Your ports on the laptop don't act this

>>>>>> way, just hubs acts this way. Most keyboards and mice are USB 1.1

>>>>>> devices. Just something to think about.

>>>>>

>>>>> What utter rubbish.

>>>>>

>>>>> If it did, it would be a complete violation of the USB 2

>>>>> specification. In fact what is required is that a fully USB2

>>>>> compliant hub is required to upconvert any low or fast speed

>>>>> peripheral communication to the fast speed for onward

>>>>> transmission. I am not aware of any USB2 hub chipset that behaves

>>>>> the way you say.

>>>>

>>>> Yeah well what can I say? I know how it is supposed to work, but it

>>>> doesn't appear to work that way to me. I am staring at my Cable to

>>>> Go Hi-Speed 4 port USB (2001 era I think) Hub and when I connect

>>>> any device slower other than 480Mb/s (USB 2.0) everything goes to

>>>> crap for bandwidth. And I will sometimes get errors stating this

>>>> device is connected to a slower than an USB 2.0 port. I am not

>>>> alone with this problem either.

>>>

>>> I can only suggest that something is wrong with your hub.

>> Nope that is the way hubs work. Single TT hubs can only allow 12Mb/s

>> for all 1.0 and 1.1 devices connected to it. And this takes away

>> from your 480Mb/s total.

> I suggest that you go and read the USB2.0 specification. Such a hub

> cannot be described as USB2 compliant - and it wouldn't work anyway

> (see below).

>>>> "As long as you don't mix USB 1.1 & USB 2.0 stuff on the same hub,

>>>> you will be fine. A simple rule is to keep all USB 1.1 to the root

>>>> ports, and connect all Hi-Speed to the USB 2.0 hub."

>>>>

>>>> http://www.everythingusb.com/belkin_tunesync_for_ipod.html

>>>

>>> I don't know where he gets this strange idea from. I have USB1 and

>>> USB2 stuff connected to the same 7 port hub (and it's a Belkin), and

>>> I get full 480 Mbps speed out of all the USB2 devices. USB2 hubs

>>> actually contain duplicated ports in a similar way to each root port

>>> actually having two root hubs and two controllers (they can't

>>> possibly work any other way).

>> Key word is total. Yes you can get 480Mb/s total. But if each device

>> wants 480Mb/s per device it just isn't going to happen. Since the

>> port the hub is plugged into can only handle 480Mb/s max. If you got

>> 7 devices wanting 480Mb/s at the same time, as you would be trying

>> to push 3360Mb/s through a 480Mb/s USB 2.0 port on your laptop.

>>>> So how it is supposed to work vs. how it really works are two

>>>> different things. I don't know? Blame manufactures claiming they

>>>> are Hi-speed USB when they really are not. Blame single transaction

>>>> translator (TT) USB 2.0 hubs which can get overwelmed with 1.1

>>>> (12Mb/s) devices? I don't know what is the reason M.I.5¾? But I do

>>>> know mixing Hi-Speed (2.0) with other speeds on a Hi-Speed hub

>>>> usually doesn't work very well for bandwidth.

>>>

>>> As I said, the spec requires that USB2 (high speed) hubs upconverts

>>> the fast and slow devices to high speed so the impact on the

>>> bandwidth should be no more than the impact of adding more high

>>> speed devices. This came about because the impact on bandwidth of

>>> adding more than one or two slow devices to a pure USB1 system was

>>> almost intolerable. All the USB2 hubs that I am aware of behave

>>> according to the spec. There is a part of the spec that states that

>>> if you have both USB2 and USB1 hubs that the USB1 devices should be

>>> connected to the USB1 hub but this is is purely to avoid

>>> unnecessarily occupying a USB2 port (and I wonder if this is what

>>> that author is getting confused with). The USB1 hub can, of course,

>>> be plugged into a USB2 hub.

>> Well having many 1.1 devices on a single TT USB 2.0 hub is bad

>> because all 1.1 and even 1.0 devices can have only 12Mb/s total from

>> the hub.

>> All 2.0 devices get the rest of the 480Mb/s. Well 468Mb/s actually

>> in this case. Multiple TT hubs can fix the 1.0 and 1.1 problem. But

>> it eats even more away from your 480Mb/s total. As each 1.0 can cost

>> you 1.5Mb/s and each 1.1 can cost you 12Mb/s.

> Absolute rubbish. All slow and fast communication must be up

> converted to 480 Mbps for onward transmission. Read the USB2.0 spec

> and you will see that this is so. A hub operating as you describe

> cannot be described as USB2.0 compliant, and wouldn't work with fast

> and slow signals. Even if you connect a USB1.0 compliant hub to a

> USB2.0 hub, although the USB1 hub does not convert, the USB2 hub must

> upconvert all the communication. Since the USB2 hub is ultimately

> connected to the enhanced host port, this must be so as the enhanced

> port is unable to handle fast or slow communication (the port

> required to do so is technically very different).

Well I suggest you read the following article and tell me what you
disagree with:

http://www.embedded.com/columns/technicalinsights/193501794?_requestid=70488

As this is how all USB 2.0 hubs are designed and work in the real world.

"Brian Ellis is a Product Manager in the Consumer & Computation Division
at Cypress Semiconductor Corp. He is currently responsible for defining,
developing, and supporting all USB mass storage solutions, USB hubs and
USB embedded host controllers."

--
Bill

Posted by Roy on April 17, 2008, 6:27 pm

Please log in for more thread options

> M.I.5=BE typed on Thu, 17 Apr 2008 08:04:29 +0100:

> >> M.I.5=BE typed on Tue, 15 Apr 2008 08:07:25 +0100:

> >>>> M.I.5=BE typed on Mon, 14 Apr 2008 07:54:27 +0100:

> >>>>>> Whoa Roy! Nobody has told you this yet and this is very

> >>>>>> important! Here is how USB hubs work! And USB 2.0 hubs are

> >>>>>> really USB 2.0 hubs, but here is the catch.

> >>>>>> If you connect up any USB 1.1 device to the hub, the whole hub

> >>>>>> drops down to 1.1 speeds. Your ports on the laptop don't act this

> >>>>>> way, just hubs acts this way. Most keyboards and mice are USB 1.1

> >>>>>> devices. Just something to think about.

> >>>>> What utter rubbish.

> >>>>> If it did, it would be a complete violation of the USB 2

> >>>>> specification. =A0In fact what is required is that a fully USB2

> >>>>> compliant hub is required to upconvert any low or fast speed

> >>>>> peripheral communication to the fast speed for onward

> >>>>> transmission. I am not aware of any USB2 hub chipset that behaves

> >>>>> the way you say.

> >>>> Yeah well what can I say? I know how it is supposed to work, but it

> >>>> doesn't appear to work that way to me. I am staring at my Cable to

> >>>> Go Hi-Speed 4 port USB (2001 era I think) Hub and when I connect

> >>>> any device slower other than 480Mb/s (USB 2.0) everything goes to

> >>>> crap for bandwidth. And I will sometimes get errors stating this

> >>>> device is connected to a slower than an USB 2.0 port. I am not

> >>>> alone with this problem either.

> >>> I can only suggest that something is wrong with your hub.

> >> Nope that is the way hubs work. Single TT hubs can only allow 12Mb/s

> >> for all 1.0 and 1.1 devices connected to it. And this takes away

> >> from your 480Mb/s total.

> > I suggest that you go and read the USB2.0 specification. =A0Such a hub

> > cannot be described as USB2 compliant - and it wouldn't work anyway

> > (see below).

> >>>> "As long as you don't mix USB 1.1 & USB 2.0 stuff on the same hub,

> >>>> you will be fine. A simple rule is to keep all USB 1.1 to the root

> >>>> ports, and connect all Hi-Speed to the USB 2.0 hub."

> >>>>http://www.everythingusb.com/belkin_tunesync_for_ipod.html

> >>> I don't know where he gets this strange idea from. =A0I have USB1 and

> >>> USB2 stuff connected to the same 7 port hub (and it's a Belkin), and

> >>> I get full 480 Mbps speed out of all the USB2 devices. =A0USB2 hubs

> >>> actually contain duplicated ports in a similar way to each root port

> >>> actually having two root hubs and two controllers (they can't

> >>> possibly work any other way).

> >> Key word is total. Yes you can get 480Mb/s total. But if each device

> >> wants 480Mb/s per device it just isn't going to happen. Since the

> >> port the hub is plugged into can only handle 480Mb/s max. If you got

> >> 7 devices wanting 480Mb/s at the same time, as you would be trying

> >> to push 3360Mb/s through a 480Mb/s USB 2.0 port on your laptop.

> >>>> So how it is supposed to work vs. how it really works are two

> >>>> different things. I don't know? Blame manufactures claiming they

> >>>> are Hi-speed USB when they really are not. Blame single transaction

> >>>> translator (TT) USB 2.0 hubs which can get overwelmed with 1.1

> >>>> (12Mb/s) devices? I don't know what is the reason M.I.5=BE? But I do

> >>>> know mixing Hi-Speed (2.0) with other speeds on a Hi-Speed hub

> >>>> usually doesn't work very well for bandwidth.

> >>> As I said, the spec requires that USB2 (high speed) hubs upconverts

> >>> the fast and slow devices to high speed so the impact on the

> >>> bandwidth should be no more than =A0the impact of adding more high

> >>> speed devices. =A0This came about because the impact on bandwidth of

> >>> adding more than one or two slow devices to a pure USB1 system was

> >>> almost intolerable. =A0All the USB2 hubs that I am aware of behave

> >>> according to the spec. =A0There is a part of the spec that states that=

> >>> if you have both USB2 and USB1 hubs that the USB1 devices should be

> >>> connected to the USB1 hub but this is is purely to avoid

> >>> unnecessarily occupying a USB2 port (and I wonder if this is what

> >>> that author is getting confused with). =A0The USB1 hub can, of course,=

> >>> be plugged into a USB2 hub.

> >> Well having many 1.1 devices on a single TT USB 2.0 hub is bad

> >> because all 1.1 and even 1.0 devices can have only 12Mb/s total from

> >> the hub.

> >> All 2.0 devices get the rest of the 480Mb/s. Well 468Mb/s actually

> >> in this case. Multiple TT hubs can fix the 1.0 and 1.1 problem. But

> >> it eats even more away from your 480Mb/s total. As each 1.0 can cost

> >> you 1.5Mb/s and each 1.1 can cost you 12Mb/s.

> > Absolute rubbish. =A0All slow and fast communication must be up

> > converted to 480 Mbps for onward transmission. =A0Read the USB2.0 spec

> > and you will see that this is so. =A0A hub operating as you describe

> > cannot be described as USB2.0 compliant, and wouldn't work with fast

> > and slow signals. =A0Even if you connect a USB1.0 compliant hub to a

> > USB2.0 hub, although the USB1 hub does not convert, the USB2 hub must

> > upconvert all the communication. =A0Since the USB2 hub is ultimately

> > connected to the enhanced host port, this must be so as the enhanced

> > port is unable to handle fast or slow communication (the port

> > required to do so is technically very different).

> Well I suggest you read the following article and tell me what you

> disagree with:

> http://www.embedded.com/columns/technicalinsights/193501794?_requesti...

> As this is how all USB 2.0 hubs are designed and work in the real world.

> "Brian Ellis is a Product Manager in the Consumer & Computation Division

> at Cypress Semiconductor Corp. He is currently responsible for defining,

> developing, and supporting all USB mass storage solutions, USB hubs and

> USB embedded host controllers."

> --

> Bill- Hide quoted text -

> - Show quoted text -

Hmm..very interesting article Bill...It sums up that not all High
Speed USB hubs are created equal....
Roy

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