Power for external HDD on Raspberry PI

[claudiu.l93]

Hello,

I want to build a home server with Raspberry PI and I want to attach a 500 gb external HDD.

My question is : The hdd has not a dedicated power supply, just the usb cable. If I will connect it directly to Raspberry PI, do I need a dedicated power supply just for the HDD ?

If yes, which power supply should I use ?

Thank you!

[gkreidl]

Yes, if you have a B+ or RPi2. You need a really good 5V2A power supply (get one of those with a cable attached directly).
In /boot/config.txt you have to add:
max_usb_current=1
Don't add other high power (>100mA) USB peripherals.

[fruitoftheloom]

Yes, if you have a B+ or RPi2. You need a really good 5V2A power supply (get one of those with a cable attached directly).
In /boot/config.txt you have to add:
max_usb_current=1
Don't add other high power (>100mA) USB peripherals.

This is a good quality PSU

https://www.raspberrypi.org/products/un ... wer-supply

[AxelStone]

Don't add other high power (>100mA) USB peripherals.

Why? Power Supply will not support it? Perhaps if exists some power supply of 3A, could it be?

[gkreidl]

Don't add other high power (>100mA) USB peripherals.

Why? Power Supply will not support it? Perhaps if exists some power supply of 3A, could it be?

No,the maximum USB current for all 4 ports together is either 0.6 A (default) or 1.2 A (if the config option is set). A HDD may draw between 600-900 mA when the motor when is spinning up.

[fruitoftheloom]

https://www.raspberrypi.org/help/faqs/#power

[carriba]

Prefer the use of an active USB hub, meaning, a USB hub that is powered by an external power supply. Do not rely on the RPi to provide suficient juice to your USB HDD when connected to ist USB port.

[JMK8]

I have an internet gateway/fileserver/firewall... box with two Pi's and disk drive all powered via a generic 5V 5A PSU. So as to not draw the drive current through the Pis USB port I carefully removed the sleeving of the drive USB cable and cut the 5V wire. The 5V feed to the drive I then fed direct from the 5V power supply. I also feed the Pis direct from the 5V 5A PSU. With a bit of soldering it works for me

[fruitoftheloom]

http://store.wdc.com/store/wdeu/en_GB/D ... iDrive_Kit

[gkreidl]

Prefer the use of an active USB hub, meaning, a USB hub that is powered by an external power supply. Do not rely on the RPi to provide suficient juice to your USB HDD when connected to ist USB port.

I'm running two RPis from HDDs, directly connected to USB. Rock solid. No need to have another 5V2A power supply for the hub running.

[asdbimbaj]

If you want to power your hdd just add too your /boot/config.txt configuration directive max_usb_current=1

Setting max_usb_current=1 sets the available current over USB to 1.2A (default is 600mA)

[fruitoftheloom]

If you want to power your hdd just add too your /boot/config.txt configuration directive max_usb_current=1

Setting max_usb_current=1 sets the available current over USB to 1.2A (default is 600mA)

Very strange that information was already posted

viewtopic.php?f=28&t=125176#p839250