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How many USB ports needed and supported?



 
 
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  #1  
Old December 31st 10, 05:00 PM posted to microsoft.public.windowsxp.hardware
James Silverton[_2_]
external usenet poster
 
Posts: 318
Default How many USB ports needed and supported?

Hello All!

I am having to plan a shift to a new desk top machine. At the moment, it
seems I would need 6 external USB ports and it looks like another 2
might be useful as spares. I want to do as little plugging and
unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am
assuming that the machine would support a cordless keyboard and mouse
without dedicated external ports.

Thanks for any assistance.




--


James Silverton
Potomac, Maryland

Email, with obvious alterations:
not.jim.silverton.at.verizon.not

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  #2  
Old December 31st 10, 05:00 PM posted to microsoft.public.windowsxp.hardware
philo[_3_]
external usenet poster
 
Posts: 239
Default How many USB ports needed and supported?


"James Silverton" wrote in message
...
Hello All!

I am having to plan a shift to a new desk top machine. At the moment, it
seems I would need 6 external USB ports and it looks like another 2 might
be useful as spares. I want to do as little plugging and unplugging as
possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am assuming
that the machine would support a cordless keyboard and mouse without
dedicated external ports.

Thanks for any assistance.





Nope

don't make that assumtion...

cordless keyboards and mice generally come with a reciever/transmitter


  #3  
Old December 31st 10, 05:17 PM posted to microsoft.public.windowsxp.hardware
Stefan Patric[_3_]
external usenet poster
 
Posts: 229
Default How many USB ports needed and supported?

On Fri, 31 Dec 2010 11:00:32 -0500, James Silverton wrote:

Hello All!

I am having to plan a shift to a new desk top machine. At the moment, it
seems I would need 6 external USB ports and it looks like another 2
might be useful as spares. I want to do as little plugging and
unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am
assuming that the machine would support a cordless keyboard and mouse
without dedicated external ports.


Any cordless keyboard/mouse combo I've ever come across needs a dedicated
USB port for the transceiver.

If you run out of USB ports, you can always add a multi-usb port card or
two. They're quite cheap.

Stef

  #4  
Old December 31st 10, 06:03 PM posted to microsoft.public.windowsxp.hardware
SC Tom[_3_]
external usenet poster
 
Posts: 4,089
Default How many USB ports needed and supported?


"James Silverton" wrote in message
...
Hello All!

I am having to plan a shift to a new desk top machine. At the moment, it
seems I would need 6 external USB ports and it looks like another 2 might
be useful as spares. I want to do as little plugging and unplugging as
possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am assuming
that the machine would support a cordless keyboard and mouse without
dedicated external ports.

Thanks for any assistance.

--

James Silverton
Potomac, Maryland

Email, with obvious alterations:
not.jim.silverton.at.verizon.not


If you are going to be leaving a lot of this stuff plugged in all the time,
you might want to invest in a powered USB hub. The USB bus on the
motherboard will only supply so much power before devices start dropping
out, or the bus is overloaded and damaged. They're fairly inexpensive and
worth it in the long run.
Here are a couple to consider:

http://www.newegg.com/Product/Produc...82E16817182212

http://www.tigerdirect.com/applicati...7BBTkwCjCECjCE

I bought this one 2 years ago when I was having power problems with my USB
sound card and an Xbox 360 controller:

http://www.datavis.com/ZONET-7-PORT-...HUB-W-POW.html

It has worked flawlessly for me. I plugged it into one of the rear USB
ports, and that leaves my front ones free for use with my pen drives and my
external HDD that I use for system images.
--
SC Tom
-There's no such thing as TMI when asking for tech support.

  #5  
Old December 31st 10, 09:41 PM posted to microsoft.public.windowsxp.hardware
Paul
external usenet poster
 
Posts: 18,275
Default How many USB ports needed and supported?

James Silverton wrote:
Hello All!

I am having to plan a shift to a new desk top machine. At the moment, it
seems I would need 6 external USB ports and it looks like another 2
might be useful as spares. I want to do as little plugging and
unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am
assuming that the machine would support a cordless keyboard and mouse
without dedicated external ports.

Thanks for any assistance.


When you shop for a motherboard, they come with USB ports in two
places.

On the back of the computer, in the I/O plate area, you could find
stacks of USB ports.

Inside the computer, on the surface of the motherboard, there
are additional 2x5 pin headers. It takes four pins, to support
a single USB port. A 2x5 header, supports two USB ports (plus
a ground signal for the shield).

By using a "slot cover adapter", you can plug a cable assembly to the
2x5 header, and that gives two additional ports on the back. If you
use enough of those adapters, you could have as many as twelve USB
ports on the back, six in the I/O area, six as three adapter plates
or eight in the I/O, four on adapter plates.

This one has 8 USB on the back, even without adapters. The two red
ones at the top of the red stack are USB. Two stacks of two are USB.
And the one with the LAN connector, has two USB.

http://images17.newegg.com/is/image/newegg/13-131-402-S08?$S640W$

And this is an example of a "quad USB adapter bracket". This
has two, 2x5 cables on the end. The adapter fits where a
PCI card slot cover would go. As long as the motherboard has the USB
headers, then the ports will work.

http://web.archive.org/web/200610310...=951&catid=226

On this motherboard, the two, dark blue connectors on the right
edge of the board, are the 2x5 connectors. By using the quad
adapter plate, that brings the total usable USB ports to 12.

http://images17.newegg.com/is/image/newegg/13-131-402-S09?$S640W$

The 12 ports are supported by the Southbridge chip. If you
need additional ports, you can install four port PCI cards
to add to the total.

(PCI version)
http://images17.newegg.com/is/image/newegg/15-124-007-S01?$S640W$

(PCI Express x1 version - bridged chip design)
http://images17.newegg.com/is/image/newegg/12-186-010-S03?$S640W$

Paul
  #6  
Old January 1st 11, 02:58 AM posted to microsoft.public.windowsxp.hardware
James Silverton[_2_]
external usenet poster
 
Posts: 318
Default How many USB ports needed and supported?

Paul wrote on Fri, 31 Dec 2010 15:41:26 -0500:

James Silverton wrote:
Hello All!

I am having to plan a shift to a new desk top machine. At the
moment, it seems I would need 6 external USB ports and it
looks like another 2 might be useful as spares. I want to do as
little plugging and unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would recommend? I am
assuming that the machine would support a cordless
keyboard and mouse without dedicated external ports.

Thanks for any assistance.


When you shop for a motherboard, they come with USB ports in
two places.


On the back of the computer, in the I/O plate area, you could find
stacks of USB ports.


Inside the computer, on the surface of the motherboard, there
are additional 2x5 pin headers. It takes four pins, to support
a single USB port. A 2x5 header, supports two USB ports (plus
a ground signal for the shield).


By using a "slot cover adapter", you can plug a cable assembly
to the 2x5 header, and that gives two additional ports on the back. If
you use enough of those adapters, you could have as
many as twelve USB ports on the back, six in the I/O area, six
as three adapter plates or eight in the I/O, four on adapter
plates.


This one has 8 USB on the back, even without adapters. The two
red ones at the top of the red stack are USB. Two stacks of
two are USB. And the one with the LAN connector, has two USB.


http://images17.newegg.com/is/image/newegg/13-131-402-S08?$S640W$


And this is an example of a "quad USB adapter bracket". This
has two, 2x5 cables on the end. The adapter fits where a
PCI card slot cover would go. As long as the motherboard has
the USB headers, then the ports will work.


http://web.archive.org/web/200610310...=951&catid=226


On this motherboard, the two, dark blue connectors on the
right edge of the board, are the 2x5 connectors. By using the quad
adapter plate, that brings the total usable USB ports to 12.


http://images17.newegg.com/is/image/newegg/13-131-402-S09?$S640W$


The 12 ports are supported by the Southbridge chip. If you
need additional ports, you can install four port PCI cards
to add to the total.


(PCI version)
http://images17.newegg.com/is/image/newegg/15-124-007-S01?$S640W$


(PCI Express x1 version - bridged chip design)
http://images17.newegg.com/is/image/newegg/12-186-010-S03?$S640W$


The only problem about installing further USB ports is whether or not
the mother board will supply sufficient current to run plugged-in
devices. I have also had interference problems with externally powered
USB hubs.

As a further question, does anyone know if any standard makers supply
USB 3.0 ports?



--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not

  #7  
Old January 1st 11, 05:47 AM posted to microsoft.public.windowsxp.hardware
Paul
external usenet poster
 
Posts: 18,275
Default How many USB ports needed and supported?

James Silverton wrote:


The only problem about installing further USB ports is whether or not
the mother board will supply sufficient current to run plugged-in
devices. I have also had interference problems with externally powered
USB hubs.

As a further question, does anyone know if any standard makers supply
USB 3.0 ports?


The motherboard has fuses installed at a rate of one 1.0+ amp fuse for
every two ports. On a 12 port motherboard, that is a total of 6 fuses.
They would be connected to +5VSB (a mistake).

In the past (perhaps three years ago), you could get motherboards with
USBPWRxx jumper plugs on them. Such a setup, allowed all the USB ports
to be run from +5V or +5VSB. The former is used, for raw power. The
latter is selected, for those ports you want to serve as a wake up
function. For example, on one of those older motherboards, keyboard and
mouse would be run from +5VSB, while the other USB ports would be
jumpered to +5V. That gives the best of both worlds. Wake-up capability
(press key on keyboard, or move the mouse, and the computer starts),
as well as giving plenty of power to the other ports. By providing
jumper plugs, one jumper per two port stack, the user had the ability
to select the right mix of +5VSB and +5V supply. By putting most of the
ports on the +5V rail, there is plenty of power. On an older
motherboard, I can run all the ports at max current.

The +5VSB rail of the power supply, has limited current. The power supply
in the computer I'm typing on, has +5VSB @ 3 amps, which is enough for
six ports at max current. If I was trying to run a dozen 2.5" USB external
hard drives, the power supply would cut out.

The motherboard really needs those old jumper blocks. The other power
path, the +5V supply, can carry about 24 amps using the wire harness
on the power supply. So that power source, could handle a dozen hard
drives at 0.5 amps each. My power supply can supply 30 amps on +5V,
so the wire harness is the rate-limiting step. And 24 amps would
be enough for 48 USB ports.

Some architect has decided to needlessly saddle +5VSB with all the
USB loads. The +5V rail has enough power to do the job, but then,
ports powered by +5V, wouldn't support waking. So to support any
USB port, being able to wake the computer, the power distribution
scheme is less than ideal.

I expect a Dell/HP/Acer would be similar. Jumper blocks removed, to
save a few pennies. And ports run from +5VSB. So there will be
limits as to the total power you can draw, and the rating on the
label of the power supply, will give the necessary details.

There are "other loads" on the motherboard, on +5VSB. My power supply
can provide 3 amps max, and 1 amp of that, is used by standby requirements
for my LAN chip, to run my keyboard (PS/2) and so on. So I might have
2 amps left "to play with". That would be enough for 4 max current USB2
loads.

Most of my USB2 devices are low power. I don't use 2.5" drives, and my
external 3.5" USB has its own power supply. My 3.5" drive would only draw a
couple milliamps from the bus connection. So in my case, the 2 amps total
would go a long way. But I can easily see, how a different set of
peripherals (lots of bus powered 2.5" USB drives), would crush that
power rail.

*******

USB3 ports, are provided solely by a NEC USB3 chip. NEC was also one
of the first companies to make the USB2 chip (before it was a standard
part of every Southbridge chip). So history is repeating itself, in
that NEC is first with a chip for the newest USB3 standard. For some
reason, both Intel and AMD/ATI, have blown it.

The NEC chip, to run at decent speed, connects to a PCI Exprees x1 Rev2
port at 500MB/sec. The chip has two, USB3 ports. You couldn't run
both ports flat out, if expecting to get record setting transfer rates.
I think the theoretical best you can do, is somewhere around 336MB/sec
(using a new protocol over USB3). Two ports couldn't transfer in the
same direction at that rate, at the same time, using the NEC chip (that
would be 672MB/sec though a 500MB/sec path). But if you were doing a
disk to disk transfer, all hardware paths are full duplex, and in fact
you can do that. (This drawing shows an unlimited transfer test case.)

PCIE x1 R2 Two
Port 336MB/sec
----- 500MB/sec ----- NEC --------------- to hard drive #2
---- 500MB/sec ------ USB3 336MB/sec
--------------- from hard drive #1

Currently, I'm not aware of a peripheral, that supports that
transfer rate. So the theoretical value, hasn't had a workout yet.
I think somewhere around 200MB/sec is the best so far (using an
SSD drive as the hard drive).

If you buy an Asus or Gigabyte motherboard, and built your own computer,
those come with the NEC chip installed. I think there are even some
motherboards, that have two of those chips installed (just for sheer
excess). It's actually hard to do a good job, due to the difficulty
of making PCIE x1 Rev2 ports using existing chipsets. A lot of motherboards
only have left-over Rev1 PCI Express lanes to work with, which prevents
getting to the theoretical max. That's one of the things I try to check,
when shopping for motherboards. If you look at the Gigabyte motherboard
user manual, it sometimes provides enough info, to determine how
the bus connection is done.

Even a broken USB3 implementation right now, will be able to sustain
the transfer rate of any single disk you buy. So it's not like
this matters much. It really depends on whether you think you'll be
able to afford a 336MB/sec device whenever such a device comes out.
The best hard drive I own, can do 130MB/sec sustained, just to show
how far from max it is.

http://www.nordichardware.com/index....ticle&id=20792

Computers from Dell/HP/Acer/Gateway, aren't likely to have that chip.
The reason is philosophy. Those companies, don't really like to
add a lot of peripheral chips to the motherboard. They usually wait
for companies like Intel, to put the necessary ports right on the
Southbridge. And that hasn't happened (for Intel's business reasons).
The idiots running the show, seem to be betting on Light Peak, to
sell a lot of product. And USB3 is falling by the wayside. Only
enthusiasts, buying their own motherboards and building their own
computers, are getting USB3 right away.

There is another way to do it. You can buy an add-in card for your
computer, and just add the ports to your Dell. Architecturally,
this is about the best of the bunch, as it tries to max the
PCIE bus bandwidth. This is a bridged design, that connects at
PCIe x4 Rev1, to give PCIe x1 Rev2 ports internally ("gear
changer chip"). But the user reviews aren't all good for this thing.
The card is cheap, but read the reviews before buying one.

(Asus U3S6 add-in card - PCI Express x4 connector)
http://www.newegg.com/Product/Produc...82E16813995004

You need an expansion slot, of either x4, x8, or x16 size, to take
that particular card. I have two x16 slots on my motherboard, with
the video card taking one slot. So I could fit that x4 card, in my
second x16 slot and use the card. That would be how I'd add USB3, at the
full rate, to my old motherboard. If you bought Dell, you'd want to
check the slot types, to find the right expansion capability to add
that.

The introduction of USB3, was one of the weirdest hardware intros
I've ever seen. The first thing to show up, were USB3 cables.
No peripherals or chips. But you could buy cabling. Next,
NEC delivered their chip. And to speed introduction, NEC
also contracted an unnamed third party, to build PCI Express x1
USB3 cards, with the NEC chip soldered to them. Many companies
bought those contract manufactured cards, for the initial release
(and rebranded the cards, by placing a sticker on them).
That helped NEC get the chips out there quickly, so they
could make some money on their design. But the funny thing
is, NEC still seems to be the "only game in town". To
the victor, go the spoils.

Paul
  #8  
Old January 1st 11, 08:12 PM posted to microsoft.public.windowsxp.hardware
Twayne[_2_]
external usenet poster
 
Posts: 4,276
Default How many USB ports needed and supported?

In ,
James Silverton typed:
Hello All!

I am having to plan a shift to a new desk top machine. At
the moment, it seems I would need 6 external USB ports and
it looks like another 2 might be useful as spares. I want
to do as little plugging and unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would
recommend? I am assuming that the machine would support a
cordless keyboard and mouse without dedicated external
ports.
Thanks for any assistance.


Dell's Precision line has 8 USB, 6 in back and 2 in front, and 2 Firewire,
one in back and one in front. They're all 2.x USB ports and all 8 work on
their own port. The back 6 are all used and I use the front 2 for things I
don't use everyday, like Livecam, one External drive that's never connected
longt-term, Digital Cam and PCTV. I have a PCI USB extender ordered & in the
mail. None of the ports double-up; all have own addresses.
I thought I'd use the one from my previous machine but this one has no
ISA ports - damn it!

HTH,

Twayne`


  #9  
Old January 1st 11, 08:14 PM posted to microsoft.public.windowsxp.hardware
Twayne[_2_]
external usenet poster
 
Posts: 4,276
Default How many USB ports needed and supported?

In ,
philo typed:
"James Silverton" wrote in
message ...
Hello All!

I am having to plan a shift to a new desk top machine. At
the moment, it seems I would need 6 external USB ports and
it looks like another 2 might be useful as spares. I want
to do as little plugging and unplugging as possible.

1 Printer
2 Scanner
3 Digital camera connection
4 UPS
5 External Hard Disc
6 Memory Stick

Are there machines with 8 ports that people would
recommend? I am assuming that the machine would support a
cordless keyboard and mouse without dedicated external
ports. Thanks for any assistance.





Nope

don't make that assumtion...

cordless keyboards and mice generally come with a
reciever/transmitter


As long as they are PS2 and not USB, that is. Otherwise USB to PS2 adapters
would be recommended where needed. Keyboards can be a little ornery so read
the specs closely.

HTH,

Twayne`


  #10  
Old January 2nd 11, 12:06 AM posted to microsoft.public.windowsxp.hardware
Ant[_3_]
external usenet poster
 
Posts: 873
Default How many USB ports needed and supported? (PS2 to USB adaptersin the rear ports = mouse pauses)

On 1/1/2011 11:14 AM PT, Twayne typed:

As long as they are PS2 and not USB, that is. Otherwise USB to PS2 adapters
would be recommended where needed. Keyboards can be a little ornery so read
the specs closely.


Recently, I got one of those PS2 to USB adapter for my two years(?) old
eMachines generic PS2 three-buttons+scroll mouse because my new
motherboard only has a PS2 keyboard port (no mouse!). I still use an old
four-ports KVM switch box from Y2K (yep a decade old) to share with
other PCs. However, my mouse likes to pause a lot with the rear USB
ports, but none in the front ports.

Any ideas why? Thank you in advance.
--
"He who storms in like a whirlwind returns like an ant." --Borneo
/\___/\ Phil./Ant @ http://antfarm.ma.cx (Personal Web Site)
/ /\ /\ \ Ant's Quality Foraged Links: http://aqfl.net
| |o o| |
\ _ / If crediting, then use Ant nickname and AQFL URL/link.
( ) If e-mailing, then axe ANT from its address if needed.
Ant is currently not listening to any songs on this computer.
 




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