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View Full Version : USB 2.0 or 1.1 cables?



technicianxp
23-02-2006, 08:26 PM
I've just recently aquired an Epson Perfection 2480 Photo scanner from my workplace. It didn't come with a USB cable so I used one from a printer which I'm going to start using sometime soon. However, when I went to look on trademe to buy another one for the printer, I found that some cables were listed as being USB 1.1 while others were USB 2.0. My scanner has a hi-speed USB logo on it so I'm pretty sure it uses USB 2.0. However, since the cable I am using is from a normal inkjet printer I'm pretty sure that it's one of those USB 1.1 cables. What I want to know is that is there really any difference in which USB standard a cable can support?

bob_doe_nz
23-02-2006, 09:29 PM
More or less its the speed difference.

USB 1.1 runs at around 1Mbps.

USB 2.0 runs at around 480Mbps.

USB 2 Cables are backwards compatible so you can use them in USB 1.1 devices.

You scanner device as you said supports USB 2 so you should theoretically notice a speedier response when scanning using a USB 2 rated cable. USB 1.1 cable will work but will e noticably slower.

Kame
23-02-2006, 09:56 PM
The question is, do you have USB 2.0 ports in your computer? Otherwise you've most likely got the USB 1.0/1.1 ports, which makes even high speed USB irrelevant, cables or devices, since they'll only run at the lowest standards available.

I'm pretty sure USB 1.1 is around 12Mbps.

If there's not much price difference in USB 2.0 cables to USB 1.1 then I'd opt for USB 2.0, they'd slightly perform better, than the USB 1.1 cables but running on a device that is not hispeed USB, then it's going to make only marginal difference, also depends on your printer, unless it's got it's own memory to store pages, it's not likely you'll be sending it 1MB straight away to the printer, hoping that it'd speed it up, the printer can only accept so much data at a time.


Cheers,


KK

bob_doe_nz
23-02-2006, 10:06 PM
I'm pretty sure USB 1.1 is around 12Mbps.
Doh! Excuse my lack of knowledge on saggy eyelids.

kingdragonfly
24-02-2006, 08:30 AM
USB 2.0 runs at around 480Mbps.
"The speeds associated with USB High-Speed and USB (480 mbps, 12 mbps, and 1.5 mbps) refer to the theoretical maximum speed of the USB interface on a USB device or USB port and really have nothing to do with the device itself.

The actual speed a USB-compliant device achieves is not necessarily the speed of the USB specification (i.e. the 'USB 2.0' specification) reflected in the product descriptions and marketing materials.

Real performance of any given product is dependent upon how fast that product can run. The device can only achieve the theoretical speeds if it can keep up with the USB data transfer rate."

http://lyberty.com/tech/terms/usb.html

technicianxp
24-02-2006, 09:55 AM
Yes I'm aware of the speed differences between the interfaces. The scanner does seem to perform okay but I'm pretty sure I could get more performance out of it if the cable does make a difference. I've got a USB 2.0 PCI card installed in my PC so support of the interface is not a problem. That's where the scanner is plugged in right now but I don't think there's any easy way of checking what speed it's performing at.
Any suggestions on where I could pick up a 1.5m or 2m cable then? It's the A/B type.

bob_doe_nz
24-02-2006, 12:23 PM
Any decent computer shop ought to sell them.

Terry Porritt
24-02-2006, 02:43 PM
There is essentially no difference between cables for USB1.1 and USB 2, provided the USB1 cables are fully compliant with USB specs:

Quote:
"2: Aren't the requirements for cables different at the new higher speed or will Original USB cables work with Hi-Speed USB?
A: Fully compliant Original USB cables will work fine at Hi-Speed USB speeds. USB cables are not all fully Original USB compliant and it is important to evaluate cables that you intend to include in your products. The USB-IF has started a program for accurately testing cables to make it easier to pick a good quality USB cable that will work correctly for both Original USB now and Hi-Speed USB in the future. You should look to the Integraters List on USB-IF Members-only section of the USB-IF web site (you will need to input your USB-IF username and password to access it) to identify products that have passed that testing program in order to minimize your risk of customer problems caused by poor cable quality."

This is from the USB bible:

http://www.usb.org/developers/usb20/faq20/

http://www.usbman.com/

Graham L
24-02-2006, 03:03 PM
The main differences are that with 1.1 you could get away with a bit. ;) A 2.0 cable will have better controlled impedance of the signal pair, and might have heavier wires (for less voltage drop).

Both of these factors will matter if you are using 5 metre long cables. With short cables, it shouldn't matter.

Shortcircuit
24-02-2006, 04:15 PM
It may not be an issue for you with an epson scanner, but my laser printer will not print at 'high resolution' unless a USB2 cable is used.

I also went out and purchased some usb cables, but could not find one that actually stated on the packet that it was USB2 compliant. I had several sales people tell me that there is no difference.

Graham L
24-02-2006, 04:25 PM
I should have said "... shouldn't matter in most cases'. :( Long cables will be much more critical, though.

Odd that the printer doesn't allow high resolution. It should just drop the data rate, and do high resolution, slowly. :D

The only way for the hardware to know the difference is to send messages back and forth at the various speeds. If the highest speed stuff has errors, or doesn't get through, it will know to cut back to the 1.1 speed. If the 1.1 speed stuff doesn't get through ...

Most "reputable" manufacturers will have the 2.0 specified on the packaging, and would usually have it marked on the cable, too. Unfortunately, they don't seem to have a different mark for the plugs.

DSE cables are all 2.0 now, I think, and are marked.