iMac and USB

Discussion in 'iMac' started by Mr. Incredible, Jun 3, 2011.

  1. Mr. Incredible macrumors 6502a

    Sep 16, 2010
    Southern California
    I got the 2010 21.5'' iMac (3.06 GHz Intel Core 2 Duo, and 4 GB 1067 MHz DDR3)

    and I'm looking for a new external hard drive.

    The one that I currently have is the Maxtor One Touch 4, and I use a USB 2.0 to plug it into my iMac.

    I found a new external hard drive to get, and it uses a USB 3.0; will I be able to plug this into my iMac, or will it not work?
  2. Intell macrumors P6


    Jan 24, 2010
    Yes, USB 3 is backwards compatible with USB2.
  3. alust2013 macrumors 601


    Feb 6, 2010
    On the fence
    Yes, it will work. USB 3.0 is backwards compatible.
  4. Mr. Incredible thread starter macrumors 6502a

    Sep 16, 2010
    Southern California

    ^So, will that work?

    It's a good deal right, for a 2TB HD at 5.0 GBps with a USB 3.0?

    Will my computer get those speeds also, or less? Cause when I clicked on About this Mac, and more info, in the USB section, it says:

    Speed: Up to 1.5 Mb/sec.

    Will the 3.0 usb increase the speeds for the data transfers or will it stick with the 1.5 Mb/sec?
  5. T'hain Esh Kelch macrumors 601

    T'hain Esh Kelch

    Aug 5, 2001
    No, you'll get up to ~450 Mb/sec, which is the speed of USB2. I am not sure why the computer is displaying the speed of USB1, which is what you mention. Is that the port that the keyboard is plugged into?
  6. Mr. Incredible thread starter macrumors 6502a

    Sep 16, 2010
    Southern California
    450 Mb/sec? Sounds good to me.

    I'm not sure if it's USB1 or 2, but if you mentioned that it's 1, then I'm not sure why it's like that.

    When I clicked:
    Apple>About This Mac>More Info...>

    It opened a box. On the left side, under Contents, in the Hardware section, I clicked on USB. To the right, there are 2 sections, the USB Device Tree, and the USB Bus.

    In the USB Bus section, in the sub section IR Receiver, it says:

    Product ID: yada yada yada
    Vendor ID: yada yada yada
    Version: 0.16
    Speed: Up to 1.5 Mb/sec
    Manufacturer: Apple Computer, Inc.
    Location ID: 0xa buncha other numbers
    Current Available (mA): 500
    Current Required (mA): 100

    In the section above, the USB Device Tree.

    Where it says USB High-Speed Bus, it has:
    Photosmart C4200 series (printer)
    OneTouch (current external hard drive)
    Internal Memory Card Reader (not sure what this is)

    ^Is something wrong with my computer or settings?
  7. Badger^2, Jun 4, 2011
    Last edited: Jun 4, 2011

    Badger^2 macrumors 68000


    Oct 29, 2009
    2TB for $120 is too much.

    $90 is better:

    $120 for 3TB is even better (Coupon code "EMCKDKG36):

    Dont get hung up on speeds.

    If you want more speed, get the first drive, then add this FW800 "foot" for $20:

    You "About this Mac" should look like this:


    Internal memory card reader = SD card reader = that little slot below the DVD

  8. Mr. Incredible thread starter macrumors 6502a

    Sep 16, 2010
    Southern California
    The coupon that you posted, how long is it good for? Can I use it like in a few weeks?

    Unfortunately, my "About this Mac" doesn't look like that. It looks like this:


    I have a wireless mighty mouse, and a wireless keyboard, maybe that's the reason to why my keyboard isn't showing up in the USB section?

    Does the rest look normal, or too slow?

    I took my iMac to the apple store a few months ago to replace my display, because one side was a little messed up, and it took them a few days to fix it. You think they might've swapped anything with my iMac?

    Edit: Sorry for the low quality image. I uploaded it on photobucket, can't figure out how to make it look clearer.
  9. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
    Look at the high-speed USB buses in System Profiler. The regular USB buses are for internal devices such as the IR receiver and they don't need more than 1.5Mb/s. Your USB ports in the back are USB 2.0, providing up to 480Mb/s (~35MB/s in real world).
  10. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    The Speed: line is the speed of the device that's attached, not the speed of the USB subsystem in the iMac. Looking at my system, I have:
    • Speed: Up to 480 Mb/sec
    • Speed: Up to 12 Mb/sec
    • Speed: Up to 1.5 Mb/sec
    • Speed: Up to 480 Mb/sec
    • etc
    For my currently connected devices. Te IR Receiver for instance doesn't need any speed faster than that. Nor does a mouse need the 480Mb/s. And Bluetooth isn't very fast either, so it connects at a slower speed.

    But to answer your question. A USB 3.0 device connected to USB 2.0 will run at USB 2.0 speeds.
  11. sth macrumors 6502a

    Aug 9, 2006
    The old world
    For better performance, you might want to consider a FireWire 800 enclosure. They're noticably faster.

Share This Page