3.5 usb powered

under key features it says usb powered these drives require no power adapter, they are powered directly through the usb cable.
 
Hmm, I'm very skeptical of this. I would need to see an actual review of this before I can believe it.
 
bass4040 said:
under key features it says usb powered these drives require no power adapter, they are powered directly through the usb cable.
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A USB jack has 4 contacts, the far left of which is 5V DC with respect to the far right pin. With a normal hard drive, the PSU has to keep up with the transiant load that is HDD spin-up, or else the drive could fail to start or even cause damage. The problem becomes exponentially more difficult when your working with USB where the 5V contact *should* be able to supply a clean 5V straight off the PSU. I dont know a whole lot about interfacing with USB, but it seems to me thats a mighty big should --one which can be tinkered with in software.

Unless this new drive has some extensive fault and signal correction, this wouldn't be a good idea.
 
Western digital would do thorough testing before releasing a hard drive. A slow 5400 rpm drive.
 
bass4040 said:
under key features it says usb powered these drives require no power adapter, they are powered directly through the usb cable.
Click to expand...

It doesn't say anywhere that it requires no power adapter, only that it requires a USB connection to the computer. The power adapter is assumed.

If a company made a 3.5" that was capable of being 100% USB powered, then they will market it extensively.
 
bass4040 said:
under key features it says usb powered these drives require no power adapter, they are powered directly through the usb cable.
Click to expand...

I just read that and it says

WD website said:
Key Features

Plug-and-play simplicity - Just connect the power and plug it into a USB port to instantly add more storage to your computer.
Click to expand...
 
WD makes Element desktops and portables.

The portables go to 500GB and are USB powered and the desktop units go to 2TB and are not USB powered.

Like everyone's telling you, there are no 3.5" USB powered portable drives.
 
It's not USB powered. That would not be possible. You can even see where the DC brick plugs in, not to mention the fact that the specs sheet lists AC input voltages and frequency.
 
They changed the website specs overnight, danny and a lot of ppl at avs read it too
 
Really doesn't matter...the USB spec doesn't supply enough power for any 3.5" drive except a floppy. Your excitement was doomed to failure from the get go.
 
brycejones said:
Really doesn't matter...the USB spec doesn't supply enough power for any 3.5" drive except a floppy. Your excitement was doomed to failure from the get go.
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You can use the power from several USB ports in order to do this, but...

At least this hard drive uses 460mA @ 12V as well as 650mA @ 5V when actively using the drive. In order to step up the 5V-USB to 12V you'd need to draw a lot more than 460mA of power from a port.

You'd need to use at least four USB ports to power tha particular 3.5" hard drive.
 
A floppy drive might be pushing it.

night_2004 said:
At least this hard drive uses 460mA @ 12V as well as 650mA @ 5V when actively using the drive. In order to step up the 5V-USB to 12V you'd need to draw a lot more than 460mA of power from a port.
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1.754 Amps on 5 Volt line. That is without a loss from to dc-dc step up. its bound to be more.
 
no...a floppy drive isn't even pushing USB 1.1 (I know because I have a sony usb floppy for a superslim pro).

Though, my usb floppy is dirt slow (even in the floppy world).
 
jeremyshaw said:
no...a floppy drive isn't even pushing USB 1.1 (I know because I have a sony usb floppy for a superslim pro).

Though, my usb floppy is dirt slow (even in the floppy world).
Click to expand...
We're talking about power usage here...
 
USB 1.1 supplies less power then USB 2.0.

A floppy drive was brought up, so I responded :).
 
The power spec wasn't changed from USB1.1 (5V, 500mA) to USB2.0 (5V, 500mA). It has been increased for upcoming USB3.0 (5V, 900mA).

Either way, wattage is the better metric to use here. The lowest power 'green' drives today use about 5W under load. USB currently supplies 2.5W. We need to do better by a factor of two before it'll be feasible. That said, most USB host ports can supply more than 500mA without complaint, and if you wired it all up (with the necessary 5V->12V DC-DC converter) it might just work; you'd probably at least need some kind of starting circuit to get the motor up to speed without tripping the USB overcurrent protection, but I think you could get away with running it. It'd be out of spec though...
 
Lol, you guys, it's obvious that this particular web-page contains an omission, who says that all information on internet is 100% accurate? Someone forgot to include the power brick requirement, that's all.
 
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