I have a 2011 27" iMac and an external hard drive that connects to my iMac with a USB 3.0 cable. Of course, my 2011 27" iMac only has USB 2.0 ports, which bottlenecks me with USB 2.0 speeds ... but I am holding on to hope that I can get better speeds without investing in an expensive Firewire or Thunderbolt external hard drive. Google searches have left me frustrated. They say things like, "an adapter for USB 3.0 to Firewire 800 will only yield USB 2.0 speeds," or, "USB 3.0 cords and Thunderbolt ports are incompatible and no adapter will work." With my current setup, are there any adapters I could buy that could get me anything faster than USB 2.0 speeds? Or is my only solution to buy a different external hard drive case with Firewire 800 or Thunderbolt connections? On a side note ... has anybody had any luck upgrading an iMac's USB 2.0 ports to USB 3.0 ports?