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USB 3.0 speeds slow

Hey guys, I recently built my new computer and its working great. However, the USB 3.0 is really slow. I have the ASRock z77 Pro3 Motherboard and I'm using the back panel USB ports. When I transfer something FROM a standard USB 2.0 flash drive, I get speeds of about 20 mb/s. When I'm transferring from the computer TO the flash drive, the speeds take a dive down to around 5 mb/s. I have a WD Caviar Blue 7200 RPM 500GB HDD (refurbished.) Please help. I already installed the USB drivers on ASRock's website. Thanks!
6 answers Last reply Best Answer
More about speeds slow
  1. For USB 3.0 to work at full speed, you have to use a USB 3.0 device. If a USB 2.0 device is plugged in, the port slows down to USB 2.0 speeds.

    Write speeds on flash memory are also a lot slower than read speeds, so your write speed is not going to be as fast as your reading speed. That is probably another reason why it takes longer when transferring files to the flash drive.

    If you want more speed, you'll have to get a faster flash drive equipped with USB 3.0.
  2. Supernova1138 said:
    For USB 3.0 to work at full speed, you have to use a USB 3.0 device. If a USB 2.0 device is plugged in, the port slows down to USB 2.0 speeds.

    Write speeds on flash memory are also a lot slower than read speeds, so your write speed is not going to be as fast as your reading speed. That is probably another reason why it takes longer when transferring files to the flash drive.

    If you want more speed, you'll have to get a faster flash drive equipped with USB 3.0.


    Thanks, but shouldn't the speeds from the computer TO the flash drive be faster? It's coming off a 7200rpm hdd and going through a USB 3.0 port. It should be faster than 5mb/s.
  3. Best answer
    No, because it is a USB 2.0 flash drive. It can only do USB 2.0 speeds, it cannot magically go faster just because the port its plugged into can support higher speeds.

    Your bottleneck for writing to the drive is probably the write speed of the flash memory and not the USB 2.0 interface. 5 mb/s is probably the fastest the flash memory can write, so there isn't much you can do about that short of getting a faster flash drive.
  4. Best answer selected by elramster.
  5. Thanks for clearing that up.
  6. elramster said:
    Thanks, but shouldn't the speeds from the computer TO the flash drive be faster? It's coming off a 7200rpm hdd and going through a USB 3.0 port. It should be faster than 5mb/s.


    nope, it will be slower when you're copying data TO the USB drive because you are WRITING to the USB drive. if you were copying data FROM the USB drive then you would be READING the USB drive, and as the READ speed is quicker that the WRITE speed on the flash drive you'll get faster speeds copying data from the flash drive.

    I also second the thought that getting a faster flash drive (which uses USB3) will be the only way to make it faster.

    EDIT: posted a few minutes after you select the best answer and unofficially 'close' the thread!
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