Looking for a low power portable hdd to connect to my TV for recording/timeshifting.
My current hdd won't power-up on the 500ma ports, and I can't spare another port to get more power.
200GB will be plenty, don't need usb 3.0 or anything. The main thing is it needs to be low power.
Any suggestions?
MOD: Move to Computing forum.
I was hoping that wouldn't be the case. Any recommendation for a cheap powered usb hub that would work? Could just use it on my existing hdd if thats the case.
Using it with the existing drive is exactly what I meant. I don't have any specific recomendations, the standard says they only need to provide 500mA, so that doesn't help. If it is a USB3 hub they must provide 650mA (IIRC), but if the TV is USB2 anyway that might just be a waste of money.
It's ridiculous that any TV that implies that it can output to a hard drive doesn't do what laptops do which is provide a practical current of 700 or 800ma+ via usb2. Maybe this or another forum post would be a good place to list known powered or passive hubs that don't artificially limit current ouput to the crappy minimum standard.
Not the TV manufacturer's fault. Although not required, good hardware should limit the current to 500mA to stop faulty equipment for causing damage.
The fault (in my opinion) lies with the following:
Short sighted USB spec (USB1's fault, which to be fair was a LONG time ago).
BAD USB3 spec. Here they didn't have an excuse, they changed the electrical interface and had the opportunity to fix the problem.
Devices marketted to do this that shouldn't (ie: almost all portable drives).
There have been multiple solutions, including a 'Powered USB' which is the proper solution, but people/manufacturers are too cheap to do things properly.
USB was never intended to power anything but the simplest of devices.
There's a fairly long list of hubs here
http://elinux.org/RPi_VerifiedPeripherals#Working_USB_Hubs
Which work with the raspberry pi which should mean they'll output over 700ma. Problem is it's hard to work out which are available in australia and how much they cost here.
Check out the Western Digital Green drives
At a glance http://wdc.com/global/products/specs/?driveID=1088&language=… 2TB
Power on Read/Write is 1.7 Watts, 500mA at 5v (USB) allows 2.5 Watts
You will also need a SATA to USB adaptor/caddy but should still be able to stay under 2.5W total if you shop around and get one that is decent on both power and performance.
Regardless of the spec document I will eat my hat if that drives stays under 500mA when powered by USB.
Unfortunately that spec is only for read-writes, spin-up usually takes more power r/w. I wonder if the green drives are used in their portable elements drives? Might see if i can borrow one from a friend and see if the tv will power it sufficiently.
I think portable elements ones will be the blue drives, they are the 'standard' WD drive, green is lower power and a bit lower performance, black is more robust with longer warranty afaik
edit: actually I wouldn't be surprised if they did use the green drives in those drives
If the drive is 1.5TB or 2TB then it's a green drive, 1TB or lower is a blue drive. (54000RPM drives that is, 7200RPM drives are all Caviar Blacks)
You've tried all the ports to see if one of them provides the few extra mA that the drive needs?
An SSD ought to be OK on that power restriction, so you could look at sticking an SSD into a USB case.
If you're brave, you could try this hack, assuming you have an unused VGA port on the TV.
http://hackaday.com/2008/11/26/usb-power-from-your-vga-port/
Or I guess you could hack an HDMI cable with a USB socket to steal a spare HDMI port's 5V line
http://www.hdmi.org/installers/insidehdmicable.aspx
Yes tried all 3 ports. It works fine in the 1A port, but I'm using that to power the raspberry pi. Yes an ssd would work but far to expensive given it wont be used that often.
Interesting hacks, the tv doesn't have a vga port, will investigate the hdmi hack, but I suspect I'll just be better off buying a hub
Is 128GB enough storage?
http://www.ozbargain.com.au/node/81655
$85 and you're set. USB3 an added bonus.
Just a follow up to this, tested out my brothers 750GB WD elements hdd last night and it worked fine on the 500mA ports. I'm thinking my portable is just too old and needs more juice then your standard portable these days.
I'll pick up the cheap toshiba 500GB canvio from OW today and see how that goes tonight.
Ok I bought the Toshiba canvio 500GB and it runs fine from the TV's 500MA ports. Thanks for all the help!
As far as I know no magnetic drive can be powered off USB2 without breaking the standard. They get away with it, but it's always out of spec (500mA). USB3 is only marginally better.
You may need to either look at drives with an external supply or that are solid state.
Update: Better idea. Buy a powered USB HUB. Still a risk that it won't provide more than 500mA, but 99% of the time this will fix your problem and let you use any USB powered drive.