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SnapperOne

Is this PC USB 1.0, 1.1 or 2.0 compatible?

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How do I determine which USB format a particular machine follows; 1.0, 1.1, 2.0?

 

Trying to help a friend buy a USB HD for bulk storage, but want to make certain her system and the HD are compatible. The USB HD states it's USB 2.0 & 1.1 compatible.

 

The only reference I find under Device Manager relating to USB is that it's Intel 82801AA.

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If the drive states that it is USB 2.0 & 1.1 compatible, this probably means that it's actually a USB 1.1 device - it's being a bit cheeky, and stretching the truth a little, since USB 2 is backwards compatible with USB 1.x devices.

 

I'm not sure what the chipset you mention relates to - try searching on the Intel website or Google, that should help. Alternatively, do you know the motherboard make and model (that would be an easier way of finding out)

 

Rgds

AndyF

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i was surfing the web a little and found that it could be a 2.0 USB (at some website, somebody was talking about his system and te MB had that chipset, and he mentioned that the USB ports were 2.0)...., well, I'm not sure about it, but it can give a clue about how to start your search.

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You should be able to check by visiting the hardware website for the board. If it's anything recent it should have usb 2.0 in it no problem.

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Usually if the machine is well configured, you will see a USB 2.0 Hub under the Universal Serial Bus tree in the Device Manager.

The name may vary especially if you got a ViA based motherboard.

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If the drive states that it is USB 2.0 & 1.1 compatible, this probably means that it's actually a USB 1.1 device - it's being a bit cheeky, and stretching the truth a little, since USB 2 is backwards compatible with USB 1.x devices.

Not necessarily - you can make a USB 2.0 device that will operate at the USB 2.0 high speed, but if it is on an older USB host, then it will operate just fine at USB 1.1 full speed. See the following excerpt from the spec:

Quote:
7.1.5.2 High-speed Device Speed Identification

The high-speed Reset and Detection mechanisms follow the behavioral model for low-/full-speed. When reset is complete, the link must be operating in its appropriate signaling mode (low-speed, full-speed, or high-speed as governed by the preceding usage rules), and the speed indication bits in the port status register will correctly report this mode. Software need only initiate the assertion of reset and read the port status register upon notification of reset completion.

High-speed capable devices initially attach as full-speed devices. This means that for high-speed capable upstream facing ports, RPU (1.5 kΩ ±5%) must be connected from D+ to the 3.3 V supply (as shown in Figure 7-1) through a switch which can be opened under SW control.

After the initial attachment, high-speed capable transceivers engage in a low level protocol during reset to establish a high-speed link and to indicate high-speed operation in the appropriate port status register. This protocol is described in Section 7.1.7.5.

Just to be clear, USB 1.0 and 1.1 define low-speed (1.5 Mbps) and full-speed (12 Mbps) operation, and USB 2.0 adds high-speed (480 Mbps).

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If the drive states that it is USB 2.0 & 1.1 compatible, this probably means that it's actually a USB 1.1 device - it's being a bit cheeky, and stretching the truth a little, since USB 2 is backwards compatible with USB 1.x devices.

Not necessarily - you can make a USB 2.0 device that will operate at the USB 2.0 high speed, but if it is on an older USB host, then it will operate just fine at USB 1.1 full speed.


I stand corrected (well, at least, I sit down corrected). I didn't realise that USB devices could do both speeds - I thought it was "all or nothing" as far as USB 2 went. Every day, something new to find out!

I stick to my point though, which was that there are a lot of products out there that say they are "USB 2.0 compatible", simply because they are USB1.x devices taking advantage of USB2.0's backwards compatibility. Just because it says it's compatible with USB2, doesn't necessarily mean it is a USB2 device...

Rgds
AndyF

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Thanks to all! Will do the smart thing and open the case, read the Intel MB number and do some web-searching.

 

And, thanks for the "compatible" warning. It's just good old American marketing. A bit sneaky? Yes! Just goes to show that you need to read, be a bit skeptical, and read some more.

 

SnapperOne

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Sorry, but that's not entirely true. SP1 adds a native MSFT USB 2.0 stack, but XP (w/o SP1) can support USB 2.0 fine, with a manufacturer's driver and USB 2.0 stack.

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