Usb 2.0? [Archive] - Glock Talk

PDA

View Full Version : Usb 2.0?


nhglocker
11-28-2004, 13:06
I feel silly asking this but was unable to find a good answer on the usb.org web site. I have a few USB cables lying around most of which are the 1.0 standard but I'm certain one or two of these must be 2.0 rated so how do I know for sure?

I found under the developer's docs section of usb.org a good description of the icon and how USB 2.0 devices display a '+' symbol but as for cables it clearly states that "This guideline does not recommend use of this icon on cables and cable-connector housings."

So other than plugging them in and seeing what happens how am I to know?

srhoades
11-28-2004, 20:16
I may be wrong but I think the whole "USB 2.0 rated cable" thing is balogna. It is the rating of the device which determines the speed. A USB cable is a USB cable. Of course, if I am wrong someone will correct me.

fastvfr
11-29-2004, 15:17
Srhoades is correct again!

It is the circuitry of the root hub that controls the speed capabilities of the USB connection.

USB 1.1 = 12Mbps

USB 2.0 = 480Mbps.

1394 Firewire = 400Mbps.

I have yet to find a USB cable, no matter the age, that did not work as well with USB 2.0 as it did with USB 1.1 as the pinout is identical.

You can even replace a PCI USB 1.1 card in an elderly Pentium II Win98 machine with a new USB 2.0 card, and the driver will enable the card's chipset to allow full throughput. Then other parts might bottleneck the data stream....but it won't be the USB port itself.

Unless the cable is broken, you shouldn't have a problem. Remember that USB 2.0 is meant to be 100% backwards-compatible with all facets of USB 1.1.

Best regards,

FastVFR

nhglocker
11-29-2004, 16:13
Well I was in Best Buy tonight looking for answers and coming back with only more questions. I looked at several USB 2.0 devices and cables none of which had the plus symbol discussed at the usb.org web site. In fact other than the packaging there was no way to tell at all.

My concern over compatibility issues was not so much pinout configuration or speed negotiatian as it was the signal quality. In sort of the same way you would not want to run gigabit ethernet over cat3 cables. It makes me wonder when I see these 2.0 rated cables at three or four times the cost of their "<i>inferior</i>" 1.0 siblings.

Is this just the case of a half baked standard or are companies just not bothering to follow it correctly?

Imagine if it was this way in the firearms industry "Well the 38 specials should work in a 357 but sometimes they blow up in your face. You better buy these hi quality loads just to be sure."

srhoades
11-29-2004, 17:46
I could understand how poorly made cables could interfere with signal quality. But I would be more concerned with a cable sold on the interenet that someone is making out of there garage. Keep in mind that cables are one of those items which are marked up more than you would like to know. Therefore brand name cables like Belkin are going to cost quite a bit more as compared to a white label bag for the same exact thing. They may have gold connectors and higher quality wire on the inside, but I highly doubt it will make a difference.

Furant
11-30-2004, 08:55
Originally posted by fastvfr
Srhoades is correct again!

It is the circuitry of the root hub that controls the speed capabilities of the USB connection.

USB 1.1 = 12Mbps

USB 2.0 = 480Mbps.

1394 Firewire = 400Mbps.

I have yet to find a USB cable, no matter the age, that did not work as well with USB 2.0 as it did with USB 1.1 as the pinout is identical.

You can even replace a PCI USB 1.1 card in an elderly Pentium II Win98 machine with a new USB 2.0 card, and the driver will enable the card's chipset to allow full throughput. Then other parts might bottleneck the data stream....but it won't be the USB port itself.

Unless the cable is broken, you shouldn't have a problem. Remember that USB 2.0 is meant to be 100% backwards-compatible with all facets of USB 1.1.

Fastvfr,

Stupid question: Does this mean that my USB 1.1 hub should also work great as a USB 2.0 hub? I just got a USB 2.0 card that I'll probably put in my computer tonight and I was thinking to buy a 2.0 hub to allow easier plug-in access for my jump drive.

At least now I know to try it before I shell out the cash.

Joey