USB hubs

[kajeel]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub and is it necessary to
use a self powered one, or is one that draws its power from the PC adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer. The PC is a P4 but unfortunately only USB
1.1 at this time.

Regards
k

 

[old jon]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub and is it necessary to
use a self powered one, or is one that draws its power from the PC
adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer. The PC is a P4 but unfortunately only
USB
1.1 at this time.

Regards
k

You can stick a PCI.USB2 card in if you have a free PCI slot.
The devices you mention should work on an unpowered hub, cos` they`ve got
their own power supplies.
bw..OJ

 

[Mark Smith]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub and is it necessary to
use a self powered one, or is one that draws its power from the PC
adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer.

Besides USB, the other option would be parallel connections, right? You
don't want to do that if have USB 1. Even USB 1 would be better than
parallel. As far as performance, you won't see any difference until you
actually access the device in particular. For example, I would not even try
to do something else on my computer while my printer is printing. When I am
not using it, but it is still connected to the usb port on the back of the
computer, there is no problem.

So to answer your question directly. Yes, go put your devices on the usb
port.

 

[kajeel]

You can stick a PCI.USB2 card in if you have a free PCI slot.
The devices you mention should work on an unpowered hub, cos` they`ve got
their own power supplies.
bw..OJ

Thanks OJ. I am planning on adding Firewire (for DV Cam connection) but may
be able to add USB2 as well. Will try a hub for the time being to save
having to swap connections.

 

[kony]

Besides USB, the other option would be parallel connections, right? You
don't want to do that if have USB 1. Even USB 1 would be better than
parallel.

Oddly, parallel is usually as fast as USB1 (since EPP/ECP
has been around for years) but the primary issue you
mentioned below is the main reason not to use it, that these
legacy ports can make a system stutter.

As far as performance, you won't see any difference until you
actually access the device in particular. For example, I would not even try
to do something else on my computer while my printer is printing. When I am
not using it, but it is still connected to the usb port on the back of the
computer, there is no problem.

?? I have no trouble printing or doing other things
simultaneous to printing with USB 1 printers, other
functions on systems with USB1 only ports, but then any
otherwise actively used devices (like mouse or kbd) are not
going through the same USB port hub nor an external hub.

 

[Mark Smith]

On Thu, 8 Dec 2005 10:20:35 -0600, "Mark Smith"
Oddly, parallel is usually as fast as USB1 (since EPP/ECP

has been around for years) ?? I have no trouble printing or doing other
things
simultaneous to printing with USB 1 printers, other
functions on systems with USB1 only ports, >>>>>>


When I print, my cpu usage rises to between 80 and 85%. It doesn't stop me
from doing other things, but it slows me down to the point where I would
rather wait.

I stopped using my parallel cables on my scanner and printer over a year ago
because I finally found some 16ft usb cables, which I needed because my
printer and scanner are on the other side of the room. So I know from first
hand experience that USB 1 is better than parallel, not just in access and
speed, but also in making the cables connect and unconnect to the computer
or peripheral.

 

[Paul]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub and is it necessary to
use a self powered one, or is one that draws its power from the PC adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer. The PC is a P4 but unfortunately only USB
1.1 at this time.

Regards
k

If any of the USB peripherals are "bus powered" and draw significant
current, then you want a self-powered hub. Peripherals that don't
have their own power brick or AC line cord, will be drawing power
from the USB cable. A "self-powered" USB hub, or a PCI USB2.0 card,
can provide the needed power, without danger of an overload.

Bus powered hubs are fine, if all the connected devices are
low powered. Or, if you know that the devices get the power
they need from the wall.

A bus powered hub has one upstream port (connects to the PC) and
a bunch of downstream ports. The bus powered hub can draw up to
500mA from the PC, via the USB cable. Now, if there are four
downstream ports on the hub, the 500mA is split over all four
of the ports. If one downstream port draws the entire 500mA,
there won't be any left for the other ports. The sum of all
the power draws, of the downstream ports, has to be less than
or equal to the 500mA available on a bus powered hub.

A self powered hub will be limited by the size of the power
brick (it still might not have enough power to run all ports
at 500mA, so check that the power brick offers enough current
for the kind of loads you expect).

Here is an example of a four port self powered hub, with
2.5 amp power brick. The 2.5 amps should be more than
enough for (4) 500mA loads. Most of the value here, is the
power supply, and not the electronics inside the hub.
(I.e. You pay $40 for this, when a PCI USB2.0 card costs $14.)

http://catalog.belkin.com/IWCatProductPage.process?Merchant_Id=1&Product_Id=123917

I would look closely at the scanner and inkjet printer, as
they may put a load on their USB cables.

If you buy a PCI USB2.0 card, buy one with a NEC chip on it.
That is the best brand of chip, by reputation.

To get USB2.0 communication rates, you'll need drivers. With
Win2K or WinXP, that is achieved by using the right Service
Pack (like SP1 for WinXP). For an older OS, like Win98SE, some
drivers were written by OrangeMicro, and a good USB PCI2.0 card
will include a driver disk with Win98SE drivers bundled. If
you are buying a bare USB card, with no cables, docs, or driver
disks, make sure you can download a Win98SE driver first if you
need one, before buying the product and being disappointed.

Paul

 

[kony]

has been around for years) ?? I have no trouble printing or doing other
things
simultaneous to printing with USB 1 printers, other
functions on systems with USB1 only ports, >>>>>>


When I print, my cpu usage rises to between 80 and 85%. It doesn't stop me
from doing other things, but it slows me down to the point where I would
rather wait.

You might dig into this more, the typical system can print
and go on about whatever it was doing without waiting unless
it was doing something sensative to the slightest CPU time
like a benchmark.

I stopped using my parallel cables on my scanner and printer over a year ago
because I finally found some 16ft usb cables, which I needed because my
printer and scanner are on the other side of the room.

There are 16 ft. parallel too, but so long as it works?

So I know from first
hand experience that USB 1 is better than parallel, not just in access and
speed, but also in making the cables connect and unconnect to the computer
or peripheral.

Funny you still haven't mentioned WHY you feel it's better?
"Acess" means what? It's easier acess to run one cable and
put a hub on the other side of the room I suppose, but
otherwise?

Speed? No. Parallel is just as fast as USB1, and as I
wrote, it tends to have the issue you mentioned about USB
but USB usually doesn't. I'm not making this stuff up, try
a few other computers.

I'm suggesting that while what you report might be true on
your system, that your system should not have this issue
with USB printing, and it should not have a slower parallel
port than USB1... did you ever check the bios for the
SPP/EPP/ECP setting?

 

[kony]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub

Yes

The hub connects to a single port and all devices connected
to that hub share bandwidth with it. If you want to use
multiple USB devices simultaneously (as-in, use, not just
have connected) then put them on different port-pairs on the
motherboard.

and is it necessary to
use a self powered one, or is one that draws its power from the PC adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer. The PC is a P4 but unfortunately only USB
1.1 at this time.

Your devices may only be USB1.1 too, it may not be so
unfortunate. Any device with it's own power supply
"usually" needs no power from the hub so a non-powered hub
would be fine. There are rare cases of USB powered
scanners, but no printers AFAIK (maybe a mobile notebook
printer but nothing desktop oriented). With no devices
needing power you have no need for the powered hub.

However it's not a bad feature to have, a powered rather
than unpowered hub so if ultimate mobility of the hub isnt'
an issue (as with notebooks) and you didn't have the hub
yet, might be a good idea to get one powered so you have the
potential for other device connections in the future.

 

[Mark Smith]

We all agree he should be using USB, right?

 

[Mark Smith]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub

No, you won't notice the difference at all, assuming you were using them
previously plugged into your comp's internal USB.

and is it necessary to
use a self powered one, or is one that draws its power from the PC adequate
for this purpose

No it is not necessary. Yes, one that draws power from the PC for your
printers and scanners will be adequate.

I am pretty sure you have more than enough answers to confuse you now, but I
will tell you that I just went and unplugged the power cable from my USB
hub. My printer and scanner still worked with the hub connected only to the
PC. So did my modem and camera for that matter.

 

[Mark Smith]

Ooops. Guess what. I just plugged in my Logitech Webcam into the USB hub
without the power cable and I got a nice little popup. The popup said I did
not have enough power to run the webcam. The webcam did not have its own
power though, like my printer and scanner did.

I plugged in the power cable from the wall and XP then reinstalled the
webcam. So I am sticking with the external power, which I was using anyway.

Now the guy has really got to be confused . . . if he is reading all these
replies.

 

[kony]

We all agree he should be using USB, right?

yes, no, maybe?

For most demanding system uses, yes it seems to have lower
impact on the system but for casual use it may not make much
difference, might as well use whatever cable is handy if he
had to go seek and buy one otherwise.

That is, unless his system has some unusual problems, for
example some HP printer drivers were a PITA to get working
on USB and some PCs are set up with 5VSB USB power that is
weak due to a generic PSU. So I suppose my take is that
when all things are equal I'd use USB but when all aren't,
parallel may not be a significant compromise in many cases.

 

[DaveW]

You'd be much better off as far as signal strength to your three components
if you used a powered hub. Three devices off an unpowered hub is pushing
it.

 

[MCheu]

I am considering using a USB hub. Is there any loss of performance in items
like printers and scanners when connected via a hub and is it necessary to
use a self powered one, or is one that draws its power from the PC adequate
for this purpose. I am planning on running an inkjet printer, scanner and
small (monochrome) laser printer. The PC is a P4 but unfortunately only USB
1.1 at this time.

Regards
k

There should not be any loss in performance unless you get ridiculous
with the number of devices you connect to it. If your hub has hubs
hanging off of it and looks like a "traditional" 50s era Christmas
firetrap/outlet, then you're probably going to see some performance
degradation even if you get a bunch of USB2.0 hubs.

If you want USB 2.0 capability without upgrading the motherboard, you
can buy a PCI card with a USB controller and 2-4 ports.

Power, it depends on the device. If you're using a device that draws
power from the port, like some models of scanners, then you probably
want a powered hub. You can only really guarantee the devices get
adequate power if you plug directly into the PC or if you use a
powered hub. Other devices like printers that have a power supply of
their own might be ok in an unpowered hub. The thing is, I don't
think I've seen an unpowered USB 2.0 hub (not counting the times I
just left mine unplugged), and many modern devices require USB 2.0
support to get reliable performance.

 

[kajeel]

There should not be any loss in performance unless you get ridiculous
with the number of devices you connect to it. If your hub has hubs
hanging off of it and looks like a "traditional" 50s era Christmas
firetrap/outlet, then you're probably going to see some performance
degradation even if you get a bunch of USB2.0 hubs.

If you want USB 2.0 capability without upgrading the motherboard, you
can buy a PCI card with a USB controller and 2-4 ports.

Power, it depends on the device. If you're using a device that draws
power from the port, like some models of scanners, then you probably
want a powered hub. You can only really guarantee the devices get
adequate power if you plug directly into the PC or if you use a
powered hub. Other devices like printers that have a power supply of
their own might be ok in an unpowered hub. The thing is, I don't
think I've seen an unpowered USB 2.0 hub (not counting the times I
just left mine unplugged), and many modern devices require USB 2.0
support to get reliable performance.
---------------------------------------------
Thanks.


MCheu

Thanks everyone for the info. I ended up getting a powered 4 port hub. At
the moment, I only have the inkjet printer attached and am in the process of
setting up the new Canon Laser and plugging it into the hub also. My Canon
scanner does not have its own power so for the time being, I still have it
directly connected to the PC. The printers will only be run one at a time so
should not be a problem....the main purpose of the hub was to avoid having
to crawl under the desk to swap plugs. Very interesting to see so many
different points of view but in a way, I am glad I went shopping before
getting to read all of them....I may have had a lot more trouble reaching a
decision.
Thanks again.
k

 

[Wilson]

It was really a silly conversation here. I don't know any usb hub now that
does not come with an alternative power source. And those self powered mini
hubs are only 2-4 dollars cheaper than the powered ones.

Now that you made it clear you were using usb on the back of your computer,
it should not have been a hard decision at all to go get a USB hub that also
plugged into your power outlet.

The only difference you will notice is the fewer knee burns and back pains
from bending over to get underneath a table to get to the back of your
comp. But I am sure you have already figured that out.

On another note, you ought not tell the people who replied to you that you
pretty much ignored them and went ahead and bought the thing without even
checking this thread first.

 

[kony]

It was really a silly conversation here. I don't know any usb hub now that
does not come with an alternative power source.

They're quite common. Where'd you look?
Just picked up one the other day for free after rebate,

http://www.ecost.com/ecost/ecsplash/shop/detail~dpno~184366.asp

And those self powered mini
hubs are only 2-4 dollars cheaper than the powered ones.

I don't know about that, I've seen many people proclaim
their $24 hub was "necessarily" the only thing they could
expect to work... vs free after rebate.

I do tend to agree that the (average) small cost difference
is easily worthwhile though, I only picked up the above hub
for portable notebook scenarios.

Now that you made it clear you were using usb on the back of your computer,
it should not have been a hard decision at all to go get a USB hub that also
plugged into your power outlet.

The only difference you will notice is the fewer knee burns and back pains
from bending over to get underneath a table to get to the back of your
comp. But I am sure you have already figured that out.

???

Seems a bit harder for you to deal with USB than some?
Really not a big deal to plug in any device that's going to
stay plugged in.

On another note, you ought not tell the people who replied to you that you
pretty much ignored them and went ahead and bought the thing without even
checking this thread first.

It does tend to be safer to pick a powered hub, if it didn't
work out there was still more info presented.

 

[kajeel]

On another note, you ought not tell the people who replied to you that you
pretty much ignored them and went ahead and bought the thing without even
checking this thread first.

Sorry if you thought it rude of me not to wait to read the entire thread
before going shopping. It was the early hours of the morning (in Australia)
when I posted the message and did not get to the computer the next morning
before going out, and actually did not expect the thread to attract so many
more responses. I made my decision after reading the first few posts and
have since read all of them for future reference.
Thanks again to all who responded.