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power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 1:28 am
by skyblue
Hello,

I hope this hasn't already been answered, as I couldn't find the information specifically for the RPi 3. Can the Raspberry Pi 3 Model B power a 320 GB USB external hard drive that doesn't have its own power source. Would it eventually run into problems?

I'm not sure what to look for to see how much power the hard drive uses, and also how much the Raspberry Pi can provide for the hard drive, given its 5V 2.5A power source (not sure what that means).

Thank you.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 3:41 am
by gwillie
Check out the following post

viewtopic.php?f=24&t=5830

It's all about the amps

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 4:02 am
by Mandrewpi
I would use a powered usb hub.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 4:56 am
by skyblue
Mandrewpi wrote:I would use a powered usb hub.
I see. How about an external hard disk with its own power adapter? And the raspberry pi would still need to be powered separately, right?

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 5:15 am
by gkreidl
It works with many drives. You need a good 5V2.5A power supply with good cabling (fixed cables are much better than using separate USB cables).
The USB cable for the drive is also important; typical short USB 3 cables delivered with most USB3 HDD boxes are best.
Don't connect other power hungry devices to USB.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 7:38 am
by gkreidl
gwillie wrote:Check out the following post

viewtopic.php?f=24&t=5830

It's all about the amps
Not up to date for RPi B+, Rpi 2 or 3.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 9:51 am
by skyblue
gkreidl wrote:It works with many drives. You need a good 5V2.5A power supply with good cabling (fixed cables are much better than using separate USB cables).
The USB cable for the drive is also important; typical short USB 3 cables delivered with most USB3 HDD boxes are best.
Don't connect other power hungry devices to USB.
So that's a yes then. I'm not sure what fixed cables are. If I'm using the official Pi 3 power adapter, I should be okay? I just don't want the drive to crash and lose all data, because I'd hate to set everything up again. I guess that's always a possibility, but I just want to minimize that.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 10:00 am
by gkreidl
skyblue wrote:
gkreidl wrote:It works with many drives. You need a good 5V2.5A power supply with good cabling (fixed cables are much better than using separate USB cables).
The USB cable for the drive is also important; typical short USB 3 cables delivered with most USB3 HDD boxes are best.
Don't connect other power hungry devices to USB.
So that's a yes then. I'm not sure what fixed cables are. If I'm using the official Pi 3 power adapter, I should be okay? I just don't want the drive to crash and lose all data, because I'd hate to set everything up again. I guess that's always a possibility, but I just want to minimize that.
I'm running all my RPis from USB HDD; one of them (a RPi 2) is using a 2.5 inch WD HDD which is powered from the RPi. It's running stable for about a year now.
By "fixed" I mean a firmly attached cable.

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Mar 23, 2016 11:13 am
by skyblue
gkreidl wrote: I'm running all my RPis from USB HDD; one of them (a RPi 2) is using a 2.5 inch WD HDD which is powered from the RPi. It's running stable for about a year now.
By "fixed" I mean a firmly attached cable.
Alright. I'll try that. Thank you very much.

Re: power source for the external hard disk drive (RPi 3)

Posted: Sat Apr 02, 2016 9:10 pm
by Doogals
So I just ordered the "official" Raspberry power supply (1.5V 2.5A) for my new Pi 3:

http://ca-en.alliedelec.com/raspberry-p ... /70812913/

...and now I'm wondering if that was a mistake because my intent is to use my Pi 3 as a portable media center with a hard drive for storage?

Any thoughts?

Re: power source for the external hard disk drive (RPi 3)

Posted: Sun Apr 03, 2016 1:38 am
by gkreidl
Doogals wrote:So I just ordered the "official" Raspberry power supply (1.5V 2.5A) for my new Pi 3:

http://ca-en.alliedelec.com/raspberry-p ... /70812913/

...and now I'm wondering if that was a mistake because my intent is to use my Pi 3 as a portable media center with a hard drive for storage?

Any thoughts?
It should work with most 2.5 " HDDs. The USB3 versions come with a thick cable which is able to carry the current without voltage drop.
But don't connect other power hungry devices to the USB boards (keyboard, mouse etc. work fine).

Re: power source for the external hard disk drive (RPi 3)

Posted: Wed Oct 26, 2016 11:59 pm
by leokaishi
I am running my Raspberry Pi 3 with Kodi and 2 HDD (4TB & 1TB "Seagate") through a D-Link powered USB hub and don't seem to be having any issues.

https://www.instagram.com/p/BMIoS_ZhP6j ... manishwayz

Re: power source for the external hard disk drive (RPi 3)

Posted: Thu Oct 27, 2016 7:13 am
by HawaiianPi
I have used my Pi3 with several USB powered portable hard drives. A single drive should work with any decent 5V/2A+ power supply and good USB cables on both sides (power to Pi3 and HDD cable).

I'm using my Western Digital Passport 320GB USB 2.0 hard drive right now to backup some files.

Power input to my Pi3 is showing 5.26V with current varying in the 780mA-1.25A range. Power at the USB port is showing 4.88V and current is varying between 300-610mA (with brief spikes in current going a bit higher). I'm using a 5.3V/2.4A PSU.

I have even successfully spun up and mounted two external USB powered hard drives, but I could only use one at a time (trying to use both at once would result in intermittent drive disconnects).

The Raspberry Pi3 can supply up to 1.2A to the USB ports (all 4 ports combined). So one HDD should be easy, but two is not going to be reliable.

Besides the HDD, I also have a Logitech Unifying dongle for my wireless keyboard and mouse, plus a 16GB USB flash drive and my digital USB multimeter. WiFi is on and connected to my router. Bluetooth is on, but not in use at the moment. I'm running the latest Raspbian Jessie Pixel, fully updated. Chromium browser is open with 5 tabs, and Audacious is playing music from the flash drive. HDMI is connected to a 1080p monitor, and the analog audio out is connected to some powered speakers.

The copy operation has finished and power input is now showing 5.29V @ 700(ish)mA, while the USB port meter is indicating 5.05V @ 280mA (drive is idle, but has not spun down).

So yes, if you have a good power supply and good USB cables you can definitely run a USB hard drive from the Pi3 USB ports. But just one... if you need more than that, you'll need either a powered hub, or powered hard drives.

FYI: The USB 2.0 spec is 500mA per port, so 4 ports should be able to supply 2A. The Raspberry Pi3 is well below spec at only 1.2A.

Re: power source for the external hard disk drive (RPi 3)

Posted: Mon Nov 20, 2017 4:42 am
by jollero
How about the newer Pi3 Model B? Can it handle 2 external usb drives better?

Re: power source for the external hard disk drive (RPi 3)

Posted: Mon Nov 20, 2017 7:14 am
by sora03
jollero wrote:
Mon Nov 20, 2017 4:42 am
How about the newer Pi3 Model B? Can it handle 2 external usb drives better?
you need a quality PSU for the Pi since 2 USB HDD will eat a lot of current. I have tested only one HDD connected to Pi directly with Y-cable (24AWG-2C/28AWG-1P) powered by MP1584 DC DC buck converter. You may want a USB powered hub

Re: power source for the external hard disk drive (RPi 3)

Posted: Mon Nov 20, 2017 8:36 am
by RaTTuS
depends on the drive,
ssd ok , 2.5" probably ok , 3.5" external PSu needed
YMMV all depends

Re: power source for the external hard disk drive (RPi 3)

Posted: Tue Nov 21, 2017 7:43 am
by HawaiianPi
jollero wrote:
Mon Nov 20, 2017 4:42 am
How about the newer Pi3 Model B? Can it handle 2 external usb drives better?
Read my post that's right above yours. It answered your question before you even asked it.

Simple answer, no, if you are talking about USB powered mechanical HDD. Maybe you could get away with two WD Pi Drives, because they were optimized for low power, but for reliability a second HDD should have its own power.

Two SSD should be possible. I am running my Pi3 from an SSD now, and it peaks at about 370mAh, so two would still be well under the 1.2A supplied by the Pi3 USB ports (as long as you don't have anything else too heavy connected to the other ports).