I have mac mini i5 2.3 intergrated graphics 8gb ram 500gb hd 2011. I have partitioned in 2 (on 10.7 and one 10.9). I need 10.7 for printer so I can't remove it. Anyhow 10.9 boots from internal in 59 seconds. And I got an external hard drive from bestbuy today for 50 bucks. Toshiba 1tb usb 3.0/2.0. Unless I get the kanex thunderbolt to usb 3.0 adapter (cuz 2011 no usb 3.0) its slow. It takes 2 minutes for a fresh install of YOSEMITE. Not install. I mean boot time. Twice as slow. I will try some usb 3 docks and adapters soon. But for now just curious what you all think of YOSEMITE. How long does it take on your systems to boot. Completely shutoff and then press the power button and time it. Internal or external it doesn't matter. I'd like to hear either or both. And if anybody had usb 3.0 it would be interesting to see how fast that boots.