USB 2.0 PCI card

  • Thread starter Thread starter Dave Reid
  • Start date Start date
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Dave Reid

I've just installed a USB 2.0 5 port card in my 3 year-old PC (Athlon
XP1800) and it does not seem to work at 2.0 speeds. Does my motherboard have
to have something else installed on it for the card to work, or is the board
too old to accept the USB 2.0 format? Sorry, I don't know the type of M/B

Dave
 
I've just installed a USB 2.0 5 port card in my 3 year-old PC (Athlon
XP1800) and it does not seem to work at 2.0 speeds. Does my motherboard have
to have something else installed on it for the card to work, or is the board
too old to accept the USB 2.0 format? Sorry, I don't know the type of M/B
Click to expand...

The motherboard type should be irrelevant as to the speed of the USB
connectors - that's the beauty of having an expansion bus (you can add
any kind of functionality you want so long as it fits, though it nay
need CPU power)

There are 2 main things that I can think of:

1 = install drivers for USB 2.0, as no OS before WinXP SP1 supports it
(install them anyways even if you have XP-SP1)

2 = the PCI bus is incapable of supplying the full 480 MB/s sustained
transfer rate of USB 2.0. It has a maximum of 133 MB/s, shared amongst
all of your PCI devices (so don't expect your LAN or sound to operate
smoothly with the USB card in full swing).

How do you know that the card is not operating at 2.0 speeds - do you
get an error message that says something to the effect of 'a USB 2.0
device has been plugged into a USB 1.1 port' or is it by timing the
transfer of a known amount of data?
 
The motherboard type should be irrelevant as to the speed of the USB
connectors - that's the beauty of having an expansion bus (you can add
any kind of functionality you want so long as it fits, though it nay
need CPU power)
Click to expand...

Before a certain period, perhaps Pentium 1 era, the PCI bus
spec was such that it might not work but on a semi-modern
system that's not an issue.

There are 2 main things that I can think of:

1 = install drivers for USB 2.0, as no OS before WinXP SP1 supports it
(install them anyways even if you have XP-SP1)
Click to expand...

This is the most likely solution.

2 = the PCI bus is incapable of supplying the full 480 MB/s sustained
transfer rate of USB 2.0. It has a maximum of 133 MB/s, shared amongst
all of your PCI devices (so don't expect your LAN or sound to operate
smoothly with the USB card in full swing).
Click to expand...

USB2 has a _realized_ throughput well below 480 MegaBITS /s,
not 480 MegaBytes /s. The actual throughput of USB2
connected devices is almost always below 30MB/s (sometimes
quite a bit lower)... about 1/4 of PCI bus capacity at most.

How do you know that the card is not operating at 2.0 speeds - do you
get an error message that says something to the effect of 'a USB 2.0
device has been plugged into a USB 1.1 port' or is it by timing the
transfer of a known amount of data?
Click to expand...

The generic answer is to check Device Manager (if/when
WIndows OS), as USB2 devices will be listed at the bottom as
"Enhanced" or EHCI
 
USB2 has a _realized_ throughput well below 480 MegaBITS /s,
not 480 MegaBytes /s.
Click to expand...

Ahhh.... I always thought that it was megabytes. Figures - it is a
serial bus after all.
 
Wow, thanks for all the replies. How stupid do I feel now. What are the odds
of all these things happening at the same time?

1. There was a cd came with the card - it was a small 2-3 inch deal and was
hidden between the cardboard covers of the packaging :-)

2. when I installed the card, I must have knocked my ethernet card a little
and dislodged it. When I was asked to connect to the internet to try and
find the drivers, I had no connection, but I had 4 green lights on my
router, so I assumed it could not find any drivers online!


I have now installed all the drivers from the mini-CD and everything is
swinging along just nicely. I really need a new pc, but you know how it is
with money & wives :-)


Thanks once again for all the replies and help.

Take Care
Dave...
 
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