Bus Powered External Drives on Mac Mini

[OldMike]

As I am looking around at all the usb 2.5" drives I have laying around, I was wondering if there is a limit to the number of bus powered drives that the Mac Mini could run at one time.

I have never run more than one self powered drive on a computer before - so I was wondering if there was a limit that the Firewire/USB bus power can support.

Ideally I would love to be able to run one bus powered firewire 800 drive, and three usb bus powered drives - I'm just not sure if that is possible or advisable...

 

[tom53092]

As I am looking around at all the usb 2.5" drives I have laying around, I was wondering if there is a limit to the number of bus powered drives that the Mac Mini could run at one time.

I have never run more than one self powered drive on a computer before - so I was wondering if there was a limit that the Firewire/USB bus power can support.

Ideally I would love to be able to run one bus powered firewire 800 drive, and three usb bus powered drives - I'm just not sure if that is possible or advisable...

The USB info shows that each USB port can support 500ma.

 

[OldMike]

The USB info shows that each USB port can support 500ma.

Thanks for the info. The only thing that i was able to find was that the Firewire port is specified at 8 watts.

When looking at the specs from bus powered external drive manufacturers, I am not noticing power requirements in their tech specs (at least the drives I looked at from WD and OWC). Lacie even has some good documentation on their external bus powered drives, but yet even they do not show the requirements in their manual.

So, without being able to find any other information, is it safe for me to assume that I can have a bus powered hard drive on the FW800 and every USB port - and they would all be provided with sufficient power to run? I was wondering if there was a max output that the mini could provide, since the mini itself does not utilize much power at all...

 

[geoffreak]

My mac mini shuts off if I plug too many drives (bus powered or not) into it. I would advise you only use a couple at any one time or invest in firewire.

 

[indiekiduk]

This guy has ran 5 self-powered WD Passport Studio Firewire 800 drives off the 8W firewire port on the Macbook Pro:
http://www.photographybay.com/2012/05/24/wd-my-passport-studio-2tb-portable-hard-drive-review/

This guy has ran 4 self-powered firewire drives and gives power details:
http://apple.stackexchange.com/ques...-pro-power-2-daisy-chained-fw800-external-hds
He reckons spin up takes 4 watts so that means that 2 should work with no issues on a Mac firewire 800 port. Then more will work but might not be able to spin up at the same time as the others.

 

[jbarley]

This guy has ran 5 self-powered WD Passport Studio Firewire 800 drives off the 8W firewire port on the Macbook Pro:
http://www.photographybay.com/2012/05/24/wd-my-passport-studio-2tb-portable-hard-drive-review/

This guy has ran 4 self-powered firewire drives and gives power details:
http://apple.stackexchange.com/ques...-pro-power-2-daisy-chained-fw800-external-hds
He reckons spin up takes 4 watts so that means that 2 should work with no issues on a Mac firewire 800 port. Then more will work but might not be able to spin up at the same time as the others.

And this guy (indiekiduk) just replied to an almost 7 year old post.

 

[jacom700]

I have a bus powered SSD and a 2.5" hdd attached to mine and occasionally a 2nd 2.5" without any problem.

 

[OldMike]

This guy has ran 5 self-powered WD Passport Studio Firewire 800 drives off the 8W firewire port on the Macbook Pro:
http://www.photographybay.com/2012/05/24/wd-my-passport-studio-2tb-portable-hard-drive-review/

This guy has ran 4 self-powered firewire drives and gives power details:
http://apple.stackexchange.com/ques...-pro-power-2-daisy-chained-fw800-external-hds
He reckons spin up takes 4 watts so that means that 2 should work with no issues on a Mac firewire 800 port. Then more will work but might not be able to spin up at the same time as the others.

Thanks for the info - I was waiting a looooong time for a good answer to my question