XC-3730C
Posts: 1
Joined: Thu Jan 26, 2017 3:25 am

Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Thu Feb 15, 2018 10:31 pm

I want to put a Raspberry Pi3 PCB and a 2.5" USB 3.0 Hard Drive in a game system shell (either a PlayStation 1 or PS2) together as a file server, but I would like to power them both with the same power supply. What are my options?

MaxK1
Posts: 1045
Joined: Sun Aug 26, 2012 11:34 pm

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Fri Feb 16, 2018 6:59 pm

You will need a power supply that can deliver it's full rated current at 5V. (IMHO "wall warts" and phone chargers just aren't good enough). So,
what you need to do is estimate the max current both the pi and HDD can draw and look for supply that can deliver that much or more. Use short, fat cables from the PSU. What you don't want is a power supply that "browns out" and drops below 4.75V - Some USB devices get a bit wonky and reset when that happens. Personally, I wouldn't be comfortable with less than a 3A supply.
You are in a maze of twisty little passages, all alike.
When General Failure and Major Disaster get together, Private Parts usually suffers.

pcmanbob
Posts: 3873
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Fri Feb 16, 2018 8:29 pm

My pi3B and USB2 2.5" HD work perfectly well using the official raspberry pi 2.5A PSU with a keyboard and mouse also attached, I see no reason your USB3 HD should not work with the same PSU

https://thepihut.com/products/official- ... aspberrypi
Please only ask questions in the forum I will not answer questions sent to me directly via PM
Remember we want information.......................no information no help
The use of crystal balls & mind reading is not supported

User avatar
HawaiianPi
Posts: 2334
Joined: Mon Apr 08, 2013 4:53 am
Location: Aloha, Oregon USA

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Mon Feb 19, 2018 12:37 pm

XC-3730C wrote:
Thu Feb 15, 2018 10:31 pm
I want to put a Raspberry Pi3 PCB and a 2.5" USB 3.0 Hard Drive in a game system shell (either a PlayStation 1 or PS2) together as a file server, but I would like to power them both with the same power supply. What are my options?
A Raspberry Pi3B can supply up to 1.2A from its USB ports (total), so it should be able to power just about any portable USB hard drive as long as your other USB devices aren't too power hungry. I have used a variety portable USB hard drives on my Pi3 and they've all worked. I've even managed to successfully spin up and mount TWO portable hard drives, but I could only access one at a time (trying to access both at once would result in one of them disconnecting).

Note that the Pi3B USB ports are only USB 2.0, so you will not get full performance out of the USB 3.0 HDD, and also, USB 3.0 ports can supply up to 900mA, so USB 3.0 hard drives can be more power hungry than USB 2.0 drives (which are designed to run on only 500mA). As long as everything you have connected to the Pi3 USB ports does not exceed 1.2A (1200mA) it should work.
MaxK1 wrote:
Fri Feb 16, 2018 6:59 pm
... Personally, I wouldn't be comfortable with less than a 3A supply.
Depends on whether or not you are powering the HDD from the Pi USB ports, or independently.

You can't pull more than 2.6A total through a Pi3, or more than 1.2A total from all the USB ports combined, so a 2.5A supply is about the max you can realistically use as a PSU powering the Pi and its USB peripherals. A higher current PSU will work, but it won't give you any more power you can actually use. Now if the PSU is powering the HDD separately from the Pi3, then the extra current might be useful.
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

MaxK1
Posts: 1045
Joined: Sun Aug 26, 2012 11:34 pm

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Mon Feb 19, 2018 12:44 pm

OP was asking about powering both - he didn't say if he was expecting the pi to supply power to the drive....
You are in a maze of twisty little passages, all alike.
When General Failure and Major Disaster get together, Private Parts usually suffers.

User avatar
HawaiianPi
Posts: 2334
Joined: Mon Apr 08, 2013 4:53 am
Location: Aloha, Oregon USA

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Mon Feb 19, 2018 6:33 pm

MaxK1 wrote:
Mon Feb 19, 2018 12:44 pm
OP was asking about powering both - he didn't say if he was expecting the pi to supply power to the drive....
He didn't say he was powering the drive separately either, and powering a portable HDD from the USB port of the computer it's connected to is the normal/typical configuration.
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

MaxK1
Posts: 1045
Joined: Sun Aug 26, 2012 11:34 pm

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Mon Feb 19, 2018 6:42 pm

Whatever... It probably isn't normal to power a USB 3 device through the pi.
You are in a maze of twisty little passages, all alike.
When General Failure and Major Disaster get together, Private Parts usually suffers.

N00biPi
Posts: 1
Joined: Mon Feb 19, 2018 7:00 pm

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Mon Feb 19, 2018 7:11 pm

Would this ( https://www.modmypi.com/blog/boost-usb-current ) work to allow the usb3 drive to work on the single Pi power supply?
I'm actually in a similar situation where I want to run (on a pi2 modelB) in a car where there is only a single 12V outlet, and I have a 2.0A usb adapter. If I can get away with not using a powered hub, or inverter, it would be ideal.

pcmanbob
Posts: 3873
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Powering Rasberry Pi3 + 2.5" USB3 HDD with the same PSU?

Tue Feb 20, 2018 1:08 pm

I can tell you now you will not run a pi3B and a USB HD off of 2A USB adapter.

I tried running my pi3B and a USB2 HD off of 2A power supply had the low volt warning flash constantly, would only work with 2.5A official power supply so I would suggest you will need a good quality 12v to 5v buck converter able to handle 2.5A but you might be better with one that can handle 3A.
Please only ask questions in the forum I will not answer questions sent to me directly via PM
Remember we want information.......................no information no help
The use of crystal balls & mind reading is not supported

Return to “Advanced users”

Who is online

Users browsing this forum: Baidu [Spider], Bing [Bot] and 12 guests