5400rpm external drive - usb powered?

Hey all, I'm planning to buy the 250gb WD Passport ( http://www.newegg.com/Product/Product.aspx?Item=N82E16822136139), which is powered by the USB bus--no external power is supported. That being said, is there anyway to determine the average power requirements of drives like these? I've read that on some computers the bus doesnt provide enough juice to power the drive, which in turn would wreak major havoc. Some of these drives ship with cables that have two usb connectors, which would provide adequate power, but not on this model. Are we talking wattage, amperage, or wha? Any documentation out there that shows how much juice these drives need during heavy usage?

BTW, I'm planning to use it with my Compal IFL90, if the dang thing ever ships.

Thanks in advance,

Jojo

 

I found the WD page on this http://www.westerndigital.com/en/products/products.asp?driveid=317&language=en

But they don't talk power needs/draw. In a general way I can tell you that you won't have trouble running on USB as long as you are not using other USB that also draws power. So if at home you use a lot of USB then just buy a powered USB hub.

Probably mA's, with volts, amps and watts, if you have any two you can figure out the third.

 

aha . . . it says on the site :

"An optional cable is available for the few computers that limit bus power."

but it doesnt give a damn link! and the only other USB device I'd be using on my notebook with this external drive attached is my g5 laser mouse.

EDIT: I found the link--they want 10 bucks for that cable! I bet newegg has one, but searching for it is proving to be difficult.

Anyone have a link to one of those Y cables that hook up two USB ports to one drive?

Thanks again.

 

You might want to be the 250GB WD external shown in this thread.

Awesome deal.

 

I am really not much help with what you need but. A mouse should not be a problem low power draw, also they said for those "few", I don't think your Sager is one of those few if it ever arrives.

 

that 250 gig drive will work no problem with a standard usb cable, but i would highly recommend getting the Y adapter to keep it spinning at a constant rate. A co worker of mine has one of these babies and got WD to send him the cable free after complaining.

 

for free huh? I'm gonna have to look into that. I guess if the drive were to constantly change rates all the time, it would cause excess wear and tear on the components . . . sounds like a legit complaint--dont it?

 

Is that what you're planning to buy : WDXMS2500TN

 

IF your notebook has a 6-pin firewire port, consider a firewire enclosure instead. Besides being waaaay faster than USB, firewire also provides 3x as much bus power, so you can even use a bus-powered 7200 rpm drive if you wanted.

Just a thought.

 

according to this:
http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1481&p_created=1164135184

it shouldnt be a problem.

 

Depends for what, but yes, firewire is better for external HDDs. However, not every PC has firewire ports, so thats something to be considered.

Firewire provides 3x voltage, power... humm not so sure!

 

I would expect the Compal to be beefy enough to power the drive you mention off USB, but it unfortunately differs from laptop to laptop. One of my laptops will pwoer my external from the usb data cable, the other will not.

If speed is important to you, you could consider firewire or even an e-sata pcmica card or expresscard to go with an e-sata enclosure.

 

Yes, I've experienced this insufficient power with external hard disk drive before even with the fork-shape USB cable provided i.e. with 2 USB connectors

You can check the amperage consumption on the drive sticker itself or check its specs on the net.

Alternativey, go for another brand with lower amperage.

Few things you need to note

a) Select a hard disk with low amperage. Do not sacrifice reliability. The lowest amperage drive in the market may not be the most reliable one. Reliability includes drive maker and country of manufacture. For example a Toshiba drive manufactured in Japan is definitely more reliable than one made in Thailand or the Philippines. Some maker gives 1-2-1 exchange upon drive failure but no data recovery. FI, some 2.5" 5400rpm ATA drive amp (of about same capacity) consumption in my country

Seagate - 0.45 A
Toshiba/Samsung - 0.7A
Hitachi/IBM - 1A

b) For notebooks not all the USB ports output 500mA consistently

c) Select the hard disk casing with low power consumption too. A casing with LCD status display is sure to consume more power than a plain one.

 

Great info FOSA, thanks for that.

As far as raw performance, I'm not really concerned; I'm just using the drive as dumb storage for my files. I wont be running any programs off of it or anything. Tho I might watch a movie or two from it . . .

From the WD site, it looks like this drive is at the high end of the spec, calling for 5V (1.0A), and drawing as much as 650mA. Looks like I'll definitely be calling WD out about the cable that is conveniently NOT included. I'll let you all know if I have any luck!

 

Tom's Hardware has an excellent set of charts of 2.5" performance, including maximum current drain. USB ports normally deliver 500mA at 5V = 2.5W.

John