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USB Power Warning


Shonk
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I have heard that you can pull upto 2A from a usb port if there's no data connection

 

Anyway today i added a powered 4 port usb3 hub and some usb drives

 

USB 3 Hub into USB 3 Port on the Microserver

It comes with a USB power cable to pull extra power which was plugged into a spare USB 2 Port on the microserver

 

USB 3 Drive 1 = Straight Into port on back of microserver

USB 3 Drive 2 = HUB

USB 3 Drive 3 = HUB

64GB USB 3 Stick = HUB

64GB USB 3 Stick = HUB

 

I started off with 2 drives in the hub and a usb stick which worked fine

having a spare port left on the hub i plugged another usb stick in

 

thats where the problems started

 

One of the drives clearly wasnt getting enough power

and was load cycling the heads

 

196000 Load Cycle Retry's in smart data

1 Reallocated sector

 

Im hoping the drive isnt actually damaged im moving all the data off it atm and going to secure erase it

which should verify the Reallocated sector

 

anyway i used this in the end from my HP Touchpad

Its a 2amp USB Power Plug all is fine now..

 

So the moral of the story is dont try powering 4 devices and a hub from the microserver usb ports :o

 

http://s5.postimg.org/5strwrzmf/Untitled.jpg

 

Untitled.jpg

 

http://s5.postimg.org/w2eufkljr/View_Image_aspx.jpg

View_Image_aspx.jpg

 

 

http://s5.postimg.org/z2hwqvspj/hub.jpg

hub.jpg

 

 

 

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I know it supplies 500ma but you can pull more if there's no data connection

on alot of motherboards

 

My desktop i pull 900ma to charge my phone from a usb 2 port

 

clearly whatever the hub was pulling wasnt enough

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I picked it up knowing if it didnt work i could use the 2amp HP TouchPad power adapter i have

 

and was expecting it to work or not via internal power

Wasnt expecting one of the drives to have a fit over power

 

anyway its secure erasing atm (has been the last hour)

hopefully its ok

 

I just thought i should post about it so someone else doesnt make the same mistake

Edited by Shonk
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I know it supplies 500ma but you can pull more if there's no data connection

on alot of motherboards

 

My desktop i pull 900ma to charge my phone from a usb 2 port

 

clearly whatever the hub was pulling wasnt enough

 

It appears that it may be possible to get more than the standard 500mA current from a USB2 port if the PC manufacturer has included a charging downstream USB port.  These ports (when used with devices that include the USB Battery Charging Specification) can draw more current from a USB 2 port for charging.  The article I read says that most manufacturers put a lightning bolt beside the higher-amperage USB ports.

 

Edit - The Dell laptop I use for work has one of these higher-amperage ports and I didn't know it until I was doing the reading for this reply.

 

That being said I think you have 2 issues.

1. I don't think the Gen8 has a lightning bolt on any of the USB ports (I can't confirm this) so there may not be any higher-amperage ports on this box

2. You were trying to power a hub and not charge a battery.  The higher amperage appears to be designated for charging and requires a device with the USB Battery Charging specification.  Older devices (the article said) that don't have the battery charging specification will be limited to 500mA.

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I incorrectly presumed hp would use the same voltage rails as used on the usb 3 ports so would be fine pulling over 500ma

 

Gigabyte have been doing this for years  as have asrock

I have some 2008 ish motherboards that supply upto 2 amps for all ports

with no indication on the board apart from in the manual

 

or it may well be that it was pulling 900ma from the port but that still wasnt enough

there's no way to tell without testing the ports

 

It managed to power 2 drives and one usb stick and the hub

with no problems so it didnt do too bad

 

it was worth a shot

Edited by Shonk
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I think i got lucky

 

On power down the 196000 load cycle retry's changed to 3 for some reason

 

One sector is still reallocated i dont think there's any way to force the drive to retest the sector its most prob fine though

 

I did a Secure erase then an enhanced Secure erase no new smart errors

though the load cycle count has gone up from yesterdays 16000 odd to 17000 odd

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Umm on looking into this more i havnt actually got a sector marked off as bad

 

5,Reallocated Sectors Count 0

196,Reallocation Event Count 1

 

This is someone's explanation of Reallocation Event Count

 

The reallocation event count increases in all attempts when the drive starts the reallocation procedure. This includes all attempts when the reallocation does not complete because of a device error or when the drive finds that the reallocation is not required as the sector currently seems usable. I mean that during the reallocation the drive tries to copy all data from the problematic sector to the spare area (usually by special methods and by slower speed) and it is possible that during this, the sector seems perfect - and the drive cancels the reallocation.

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