USB 2 Devices Not Necessarily High-Speed

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.

Comments

This is old, USB already defined it

[mlrtime]

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?

Re:But do they NEED it?

[oe1kenobi]

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

The standards: Defined...

[Anonymous Freak]

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.)

Re:But do they NEED it?

[Zugok]

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.