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Sometimes, when I plug in my flash drive, it's using USB1.0 driver, instead of USB2.0 driver. Is there any like in Device Manager that I can check the driver information?

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up vote 3 down vote accepted

Well, it's kind of low-tech but if you copy a file over the wire and get more than 1 MB/sec it's USB2.0. How do you know "it's using USB1.0 driver, instead of USB2.0 drive"? Are you saying you're getting two different messages when plugging in the same drive? Or you're getting one speed on read (fast) and the other speed on write (slow)? If the latter then that's normal and the actual hi/lo speed numbers vary a LOT based of which flash drive you use.

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I am saying using same USB drive, plug in same USB slot. Sometimes the read/write rate is like USB2.0, like 20M/s. Sometimes only 4M/s, in this case, if I pull it out and plug again, it can be back to 20M/s. So looks like it doesn't plug properly can cause the OS recognize the drive incorrectly. – Stan Aug 11 '10 at 1:07
@Stan: Both those rates are way beyond USB 1.0. Per wiki "The USB 1.0 specification was introduced in January 1996. The original USB 1.0 specification had a data transfer rate of 12 Mbit/s". You've got a problem, but I don't think it's because the machine is picking the wrong USB driver. – hotei Aug 11 '10 at 2:06
@Stan: What you may be seeing are "artifacts", caused by the system caching parts of the USB drive and not others. Copy the part already cached --> fast. Copy something not in cache --> slow. Just a wild guess. If you do the copy tests right after the machine boots, before it has a chance to cache anything from USB drive you should see both times roughly same, say +/- 10%. – hotei Aug 11 '10 at 2:10
Thanks for the suggestion, will try it. – Stan Aug 11 '10 at 18:14

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