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USB 2 Devices Not Necessarily High-Speed

Posted by timothy on from the words-by-any-other-names dept.

mgcsinc writes "Yahoo is running a story on how some manufacturers of "USB 2.0" devices are making hardware compatible with the USB 2.0 standard, but not necessarily its high-speed component." Sounds like the complaint raised earlier this year.

7 of 268 comments (clear)

  1. But do they NEED it? by pfraser · · Score: 5, Insightful

    Do the devices need that high-speed component? Does a USB mouse need to be able to transmit data in excess of 400mbit/sec? No?

    1. Re:But do they NEED it? by oe1kenobi · · Score: 5, Informative
      So then a mouse should be USB 1, not 2. If it doesn't go at USB2 speeds, it shouldn't be called USB 2. Manufacturers are labeling USB 1 things as USB 2 to increase sales while deliberately misleading people. That is clearly wrong, and should be stopped.

      But is does "go at USB2 speeds": they run at the USB 2.0 "Low Speed" (1.5Mbps).

      802.11b runs at 1Mbps, 2Mbps, 5.5Mbps, or 11Mbps. USB 2.0 runs at 1.5Mbps ("Low Speed"), 12Mbps ("Full Speed", what a stupid name), or 480Mbps ("High Speed"). People just need to understand that the name of the standard doesn't relate to a specific transfer speed.

      The real problem is if manufacturers don't list on the packaging what actual data rate they do use. Don't support manufacturers that don't provide you the information you want to know.

      -Richard L. Owens
      --
      -Richard L. Owens
    2. Re:But do they NEED it? by Zugok · · Score: 5, Informative
      youare way missing the point.

      USB2 IS a protocol, it supports USB1 and USB1.1 protcols


      USB2 IS NOT a specific speed



      So if claims on a mouse says it supports USB2 but only requires the USB1.1 or USB1 protocol to work, that's okay. However if it says it runs at High Speed USB (400mbps) but really only runs at Full Speed USB (12mbps or what ever it is...) then that's false advertising.
      --
      "I just can't sit while people are saying nonsense in a meeting without saying it's nonsense" J Watson, Sci Am 288:(4)51
  2. Surprised? by Deaper · · Score: 5, Insightful

    Does this actually surprise anyone? I mean these are the same people who have been decieving consumers for years with hard drive sizes. Do you actually think they're going to tell you the device doesn't work the way it should by labeling it as such? The record industry doesn't label crippled crap. Why should the computer industry? Why do consumers actually trust producers that constantly try to implement new technology that assume that the consumer is the one that can't be trusted? Does it make me angry that the producers keep doing this kind of crap? Yes. Does it surprise me? Not in the least.

  3. This is old, USB already defined it by mlrtime · · Score: 5, Informative



    The USB2 does not signify high-speed of course. If you want USB High Speed you need to look for the high speed logo.

    as in this image here: http://www.usb.org/images/headermain/2logos.gif

    The one on the left is the high speed, one on the right is regular speed. Simple eh?

  4. The standards: Defined... by Anonymous+Freak · · Score: 5, Informative

    Okay, there are two major 'versions' of USB, and three speeds.

    USB 1.1 is the 'old' standard. USB 1.1 defined the 2Mb/s and 12Mb/s speeds ('Low speed' and 'Full speed' respectively.) USB 1.1 devices are fully compatible with USB 2.0 devices, but, of course, can only run at 12Mb/s maximum. Note that hubs that are only USB 1.1 compatible will only allow 12Mb/s maximum through them.

    USB 2.0 is the current standard. It is fully compatible with Low and Full speeds, plus adds 480Mb/s 'Hi-Speed'. Any USB 2.0 compatible controllers (computers,) can run any device that supports any of the three speeds. USB 2.0 devices that are 'Hi-Speed' are also supposed to support Full speed for compatibility (For example, that 52x CD-RW drive should support Full speed, but will drop to 4x speed, when connected to a USB 1.1 controller.)

    The official 'branding' of devices is that they should *NOT* specify USB 1.1 vs. USB 2.0. They should only say the speed they operate at. So Low or Full speed devices (mice, keyboards, printers, etc,) should have a 'USB' logo, with no version numbers, just the USB logo. 'Hi-Speed' devices (hard drives, CD-ROM drives, camcorders,) are supposed to use the 'USB Hi-Speed' logo, which, again, does not say 'USB 2.0', only adds 'Hi-Speed' to the normal USB logo. Companies that use "USB 2.0" branding to advertise any device are not complying with the USB group's marketing standards.

    But, yes, a USB 2.0-compatible device can very well operate at 2Mb/s, or 'Low' speed. A good example is keyboards with built-in hubs. My old keyboard is only USB 1.1, so I can plug in any device I want, but it will run at 'Full' speed (12Mb/s) maximum. Newer keyboards have USB 2.0-compatible hubs, so even though the keyboard itself is 'Low' speed, you can plug in your external HD, and the hard drive will happily run at 480Mb/s to your host computer. (Obviously, you also need a USB 2.0-compliant host controller in your computer.)

    --
    Another non-functioning site was "uncertainty.microsoft.com."
    The purpose of that site was not known.
  5. A lot of people fail to notice the real issue. by stvangel · · Score: 5, Interesting

    USB as well as FireWire are still a single set of wires. Unless you use some sort of USB router or multiple controllers, all the devices must share a finite amount of bandwidth based on the ratio of their speeds.

    For example: A device running at 2mb speed that sends 500kb in a second uses a full 1/4 of the entire USB bandwidth. This automatically chops the 12mb down to 9mb, and the 480mb down to 360mb. A 12mb device that sends 6mb cuts it in half.

    By the time you have a keyboard, mouse, joystick, mp3 player, external drive, and who knows what else sharing the USB connection, you have a lot of things competing for limited bandwidth with the slower devices taking an inordinate share of the pie. This is one of the reasons I like sticking to the old PS/2 style Mouse and keyboard connectors. Keep these usually slow devices from flooding the connection. Particularily the high-res mice.

    And then when you consider the 2mb/12mb/480mb numbers are the absolute maximum theoretical numbers without overhead, you realize that you get nowhere near this kind of throughput in the first place. Things can get bogged down pretty quickly.

    Personally, I run two separate USB adapters. The built-in USB on the motherboard and a separate PCI USB controller. I leave all the slow things like keyboard and mouse and joysticks on one controller. I put the things that need speed like a dvd burner or mp3 player on the other one and make sure I don't use them at the same time.