Booting from USB drive?

flashofthedark

macrumors newbie
Original poster
Aug 20, 2012
7
0
Chico, CA
I've got a 2007 20-inch iMac logic board with a broken internal SATA connector. I've tried epoxy, solder, etc. but I can't keep the part to stay on properly. Does OS X have to see an internal hard drive attached to continue boot, or can I have an external USB drive attached and have the system automatically boot to that drive upon startup without having to go through some special procedure? It's for a client of mine, he's old, and I don't want him to have to press a special key combination to get into his OS.
 

stridemat

Moderator
Staff member
Apr 2, 2008
11,179
594
UK
You can use a USB install but will need to boot the Mac while pressing the ALT key.
 

Intell

macrumors P6
Jan 24, 2010
18,883
373
Inside
Once you are started up from the external drive, you can set it to always boot from it by setting it in the Startup Disk pref pane.
 

flashofthedark

macrumors newbie
Original poster
Aug 20, 2012
7
0
Chico, CA
Once you are started up from the external drive, you can set it to always boot from it by setting it in the Startup Disk pref pane.
And I can do that with a USB drive instead of an external? Are you sure OS X will still boot without an internal HDD attached? For some reason I have a memory of OS X refusing to boot if there's no internal attached, maybe in the G4 G5 days.
 

flashofthedark

macrumors newbie
Original poster
Aug 20, 2012
7
0
Chico, CA
On some Macs, the USB ports are very slow compared to the firewire ports. Is this true for the 2007 iMac? I'm guessing I should stick with a firewire 400 enclosure for the boot drive; I want it to be about as responsive as the internal drive.
 

Intell

macrumors P6
Jan 24, 2010
18,883
373
Inside
FireWire 400 is slightly faster in real world use than USB 2. But still not as fast as the internal SATA drive. You could use the FireWire 800 port, that's almost as fast, but still slower.
 

ivnj

macrumors 65816
Dec 8, 2006
1,175
38
usb works. I even installed 10.8 to a SD card and booted no problems and lag.