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From: Paul on 18 Dec 2009 05:18
Bill in Co. wrote:

>>
>> USB2 devices are supposed to be backward compatible with USB1.1 ports.
>> So if a person has a computer with only USB1.1 ports, you can still
>> plug USB2 devices into those ports. For things like mass storage
>> devices, I would not expect a problem. Your transfer rate in
>> that case is 1MB/sec, rather than the 30MB/sec typically seen
>> on USB2 host ports.
>
> So let's see, for say 10 GB of data, at 1 MB/sec, we're looking at 10,000
> seconds, vs 333 seconds for USB 1.1. Ideally.
>
> 10,000 seconds/3600 = 2.78 hrs, vs 333/3600 = 0.093 hrs (around a tenth of
> an hour, or 6 minutes), if I didn't mess up the calculations. WOW, what a
> difference!
>
> Actually, these speeds sound a bit high (idealistic) to me, though; and
> maybe in practice it's even less, and perhaps even significantly less, but
> I'm not positive of that.
>

When I mention speeds such as 1MB/sec for USB 1.1 or 30MB/sec for USB 2.0,
those are ideal values you might see when copying a very large file to
a USB hard drive.

If there is backup software running, compressing things and generally
thrashing the heads on the source disk, it is quite possible to get
an apparently much lower transfer rate. I've had plenty of backup
software, that could only manage 5MB/sec. So having a 30MB/sec link
to the disk, isn't always the rate limiting factor.

I think you could see a 6 minute transfer time, if the 10GB of data
was available as a single file, and you wished to transfer it to
the external. I've benched with HDTune or the like, and can get
the 30MB/sec number.

If you look at the USB2 cable rate, it is 480 megabits per second.
Dividing by 8 gives 60MB/sec. Yet, the enclosures give 30MB/sec,
and the difference is due to the packet protocol used to do the
transfer. Someone did a calculation once, claiming that USB2
could give 57MB/sec under ideal (no protocol issues) type
conditions, but I'm still waiting to see a situation that
actually does that. Somewhere in the 30MB/sec range seems
to be what people can see.

Another tiny point about USB2 bandwidth, is it is shared over
multiple ports. If you use two USB2 cards, then each may manage
30MB/sec. If you connect two USB hard drives to one USB2 PCI card,
you may not get the entire 30MB/sec rate that way. For people
pushing the limitations, they may experience less than ideal
results. But if you're transferring from an internal disk
to the USB external via a USB2 PCI card, I would expect to
see 30MB/sec there. And the 6 minutes to transfer 10GB.

I've also tested a PCI USB 1.1 card (I have one in my junk box),
and when using my fast USB pen drive, I got 1MB/sec on that
one.

Paul
From: Paul on 18 Dec 2009 05:50
Roger wrote:
> "philo" <philo(a)privacy.invalid> wrote in message
>>
>> I actually have a USB 1.1 enclosure and I stopped using it years ago.
>>
>> The data transfer time was *excruciating* slow . I *highly* advise adding
>> a PCI USB-2 card to the machine. They cost very little (under $10 from
>> Newegg) and are very easy to install
>
> Changing my card seems the possibility now, would it be best to remove the
> current USB card from machine and put USB 2.0 in that slot, and are those
> leads universal for the new card type.
>
> Roger
> ++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++++++++
>

You may currently be using USB ports in the "I/O area" on the
back of the computer. Those would be ports supported by the
motherboard itself. There would be nothing to remove there.

(Picture of an I/O plate - plate snaps into computer case and surrounds built-in connectors)
(You might be using a USB connector in the I/O plate area.)

http://estore.asus.com/images/13-020010440.JPG

A desktop computer also has room for add-in cards,
with slot names such as PCI. Here, you can see a
card poking out through one of the slots used
for add-in cards. You have to look inside the computer,
to see if you have a spare (empty) slot for insertion
of an add-in card.

http://www.hardwarezone.com/img/data/articles/2008/2754/5%20-%20Faceplate%20in%20place.jpg

The slot types have names, such as ISA, PCI, AGP, PCI Express.
Each slot has a different shape and count of contacts. PCI is
a very common type, and has been present in computers for
at least ten years. There are a couple very modern motherboards
that have no PCI slots. On other machines, you might find
anywhere from 1 to 5 of those slots. My current Core2 computer
has four PCI slots (an exception).

PCI is favored currently, when seeking the cheapest add-in card
possible. PCI is what makes a $10 card possible. Other formats
may be more expensive.

This article has pictures of some PCI slots. There are big and
small sized slots, with the big ones being more popular in
server type computers.

http://en.wikipedia.org/wiki/Conventional_PCI

Your slots will look more like this. Check to see if any of them
look like this. These are spare PCI slots as seen on a home (desktop)
computer. In this picture, the faceplate area is to the left. The
key in the slot, is on the right. Having the key on the right,
means the slot accepts a 5V card (because the motherboard is using
5V I/O). PCI slots have two key positions, left and right, the left
one meaning 3.3V and the right one meaning 5V. The card only fits
in the slot, if the key fits a groove in the PCI card. The keying
is there to ensure only compatible cards can be inserted. If there
is incompatibility, you won't be able to seat the card. The keying
scheme prevents electrical mischief.

http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/PCI_Slots_Digon3.JPG/800px-PCI_Slots_Digon3.JPG

It is not as complicated as it sounds :-) Just buy it and stuff
it in. I probably wouldn't waste an extra minute thinking about
it, and would tick the box to order the $10 card. Have a quick
look inside the machine, to make sure there is physical room for
it. And that check should be enough of a precaution. If you've
filled all the slots (or Dell filled them with stuff), then you
might have to spend more time investigating what your options are.

In this picture, you can see a computer with a purple colored
AGP slot for addition of a video card. You can see how it is
set back a bit, from the left hand faceplate area. The PCI slots
are also visible in this picture.

http://upload.wikimedia.org/wikipedia/commons/d/d1/AGP_slot.jpg

So if you own an IBM PC compatible desktop, chances are good
you have PCI slots, and that a PCI card purchased at retail,
is going to fit into it. If you own a high end Apple desktop
computer, sometimes you have to stop and ask more questions.

If you want more help, please give the make and model number
of the PC, or if you built the computer from parts, the
make and model number of the motherboard used in the build.
If we can find a picture of the product, we can point out
to you, where the slots are located.

Paul
From: Roger on 18 Dec 2009 10:08

"Paul" <nospam(a)needed.com> wrote in message news:hgfmp0$973$1(a)aioe.org...
> Roger wrote:
>> "philo" <philo(a)privacy.invalid> wrote in message
>>>
>>> I actually have a USB 1.1 enclosure and I stopped using it years ago.
>>>
>>> The data transfer time was *excruciating* slow . I *highly* advise
>>> adding a PCI USB-2 card to the machine. They cost very little (under
>>> $10 from Newegg) and are very easy to install
>>
>> Changing my card seems the possibility now, would it be best to remove
>> the current USB card from machine and put USB 2.0 in that slot, and are
>> those leads universal for the new card type.
>>
>> Roger
>> ++++++++++++++++++++++++++++++++++++
>> +++++++++++++++++++++++++++++++++++++
>
> You may currently be using USB ports in the "I/O area" on the
> back of the computer. Those would be ports supported by the
> motherboard itself. There would be nothing to remove there.
>
> (Picture of an I/O plate - plate snaps into computer case and surrounds
> built-in connectors)
> (You might be using a USB connector in the I/O plate area.)
>
> http://estore.asus.com/images/13-020010440.JPG
>
> A desktop computer also has room for add-in cards,
> with slot names such as PCI. Here, you can see a
> card poking out through one of the slots used
> for add-in cards. You have to look inside the computer,
> to see if you have a spare (empty) slot for insertion
> of an add-in card.
>
{SNIP}

Paul thank for your most detailed reply which I try to absorb. I'm not
worried about getting inside PC as I often clean there and have changed the
Ram. My board is K7s5a ECS I have the manual stored in My docs in adobe
PDF but are unable to sort out getting you a picture link of mainboard.
Looking at board it shows 5 PCI slots This was a made up PC. Looking at the
back of unit one of those slots is housing four USB ports this must have
been added later on an upgrade.as on drawing it only shows one usb1 next to
fp audio,woL1,FP1, SPK1, etc . I have 3 of those slots still with the blank
fitted.

Roger
======================================
=============================


From: Paul on 18 Dec 2009 10:55
Roger wrote:

>
> Paul thank for your most detailed reply which I try to absorb. I'm not
> worried about getting inside PC as I often clean there and have changed the
> Ram. My board is K7s5a ECS I have the manual stored in My docs in adobe
> PDF but are unable to sort out getting you a picture link of mainboard.
> Looking at board it shows 5 PCI slots This was a made up PC. Looking at the
> back of unit one of those slots is housing four USB ports this must have
> been added later on an upgrade.as on drawing it only shows one usb1 next to
> fp audio,woL1,FP1, SPK1, etc . I have 3 of those slots still with the blank
> fitted.
>
> Roger

I have a K7S5A manual on disk here. (I download a lot of different manuals,
so I have a small collection.)

There are two USB ports in your I/O area.

If you already have a PCI USB card, you should check Device Manager in WinXP,
and look for the word "Enhanced" in the USB section. The technique of checking
for USB2 is described in the link below.

So it could be, you already have USB2 and it might be on that PCI card.

If you're not seeing Enhanced, then perhaps the purchase of another card
would help.

I have a really old PCI USB card, which has USB 1.1 ports only on it,
so it isn't guaranteed that your PCI USB card is USB2. But if you check
Device Manager, you may be able to save yourself $10.

http://www.usbman.com/Guides/checking_for_usb_2.htm

"NEC PCI to USB Enhanced Host Controller (B1)"

That is an example of what is coming from a PCI USB2 card with a
NEC chip on it. So that machine has USB2 capability.

Paul
From: Roger on 18 Dec 2009 14:42

"Paul" <nospam(a)needed.com> wrote in message news:hgg8k3$3m8$1(a)aioe.org...
> Roger wrote:
>
>>
>> Paul thank for your most detailed reply which I try to absorb. I'm not
>> worried about getting inside PC as I often clean there and have changed
>> the Ram. My board is K7s5a ECS I have the manual stored in My docs in
>> adobe PDF but are unable to sort out getting you a picture link of
>> mainboard. Looking at board it shows 5 PCI slots This was a made up PC.
>> Looking at the back of unit one of those slots is housing four USB ports
>> this must have been added later on an upgrade.as on drawing it only shows
>> one usb1 next to fp audio,woL1,FP1, SPK1, etc . I have 3 of those slots
>> still with the blank fitted.
>>
>> Roger
>
> I have a K7S5A manual on disk here. (I download a lot of different
> manuals,
> so I have a small collection.)
>
> There are two USB ports in your I/O area.
>
> If you already have a PCI USB card, you should check Device Manager in
> WinXP,
> and look for the word "Enhanced" in the USB section. The technique of
> checking
> for USB2 is described in the link below.
>
> So it could be, you already have USB2 and it might be on that PCI card.
>
> If you're not seeing Enhanced, then perhaps the purchase of another card
> would help.
>
> I have a really old PCI USB card, which has USB 1.1 ports only on it,
> so it isn't guaranteed that your PCI USB card is USB2. But if you check
> Device Manager, you may be able to save yourself $10.
>
> http://www.usbman.com/Guides/checking_for_usb_2.htm
>
> "NEC PCI to USB Enhanced Host Controller (B1)"
>
> That is an example of what is coming from a PCI USB2 card with a
> NEC chip on it. So that machine has USB2 capability.
>
>

Paul It looks a basic set to me, e.g. showing 1 Logitech Camera, 1
Generic USB hub, 4 Lucent QuadraBus host Controller, 2 SIS 7001 PCI to USB
host, 6 USB Root Hub.

Roger


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