I've been looking at those too.

A couple of questions about them which I cannot find an answer to:

1. They come with a mains adapter, but can they run with power from the USB connection?

2. When the Mac is turned off and the USB effectively inactive, do the drives power down or go to an idle state?

I can't give an authoritative answer to either of those, but I'm pretty sure the answer to 1) is no- it's a 12v 1.5A PSU for one thing, and the most a USB port is spec'ed to provide is 500mA. I'd think the start-up surge would kill a USB port supply, and I've never yet seen a decent-sized HDD that would run from USB power only.

As for 2), I never turn my Mac off, so hard to say . Not sure what you mean by "power down" and "idle", if it were completely powered down it wouldn't restart when the USB became active again afaics.

It's set to "sleep" (in sysprefs) after a period of non-use and appears to spin down, though obviously the interface electronics have to stay "live".

HTH

I have a 1TB WD MyBook. When I put my PC into standby (suspend to RAM), the MyBook powers off. Ditto shutdown.

Point 1. Best guess is no they can't run power from USB.

From WD's site:

Plug-and-play simplicity.
Just connect the power and plug it into a USB port to instantly add more storage to your computer.

I guess they're more marketed for mobile users (meaning people with laptops, as opposed to roaming profile folk with a drive in their pocket). The draw on these bigger drives can mess with laptop mobo/USB power capacity apparently.

I don't quite see the point of them in that sense. Might as well have a NAS solution if it's a static drive, and cloud solution otherwise.

I've got one of those on the PVR. If I put it into standby the actual drive spins down (ie powers off) but the unit as a whole remains on, ie the indicator lights on the front are still active.

I think there may be some confusion here between the external unit and the actual disc drive itself?

Western Digital Passport drives run from USB only and they are available in 1TB and 2TB versions.

A drive should be able to fully power down provided there is a control circuit to bring it back to life when the USB port becomes active again.

I want to use the drive for the PVR function on my television which is powered down for around 18-20 hours/day.

The WD Passport drives in 1TB & 2TB are USB only and those are ideal for laptop users.

In reply to a post by MHC:

Western Digital Passport drives run from USB only and they are available in 1TB and 2TB versions.

Fair enough... presumably if this one could run from USB-only it would be a Western Digital Passport and not a Western Digital Elements

In reply to a post by MHC:

I want to use the drive for the PVR function on my television which is powered down for around 18-20 hours/day.

Ah, here we have the difficulty again... I doubt you want to use the PVR function of your TV while it is powered down. In standby, yes, powered down, no. Powered down means OFF, mains (or whatever) not connected to any of the innards, not even the sensor for the remote. It's effectively dead- and safe to take the back off

Same goes for external drives- if it's powered down, it's OFF. If it's in standby (or "idle", maybe), the platters aren't spinning but the electronics is still (mostly) running.

Using the PVR function of your TV, can you record direct to an external drive? My Humax will only record to its internal drive, I have to copy it to the external MyBook later.

Edited by billford (Fri 16-Nov-12 00:26:04)

The TV requires an external drive on one of the USB ports.

If the TV is in full standby then the USB appears to be totally OFF, when in operational/record mode the USB is active. So, when the TV goes into standby - effectively off, I'd like the drives to go into an "OFF" or standby mode which needs to be auto.