USB 3.0 external 3.5" drive without power adapter?

[gggirlgeek]

Is it possible to have an External USB 3.0 enclosure (for Sata 3.5" HDD) with no power adapter requirement??? Most of the External enclosures I've seen on Newegg have a power adapter. (I see some 2.5" models without them though.) Is this for backup/extra boost or is it needed?

I'm on my last decision before buying all the parts needed for my new system build. The last part: The desktop case.

The difference: The front port either has eSata or USB 3.0 connection. eSata is faster so if I need a power adapter anyway than who needs the USB 3.0?? Know what I mean?

3.5" USB 3.0 Enclosure

 

[Hawkeye22]

I don't think a USB port can provide enough power for a 3.5" drive, thus the need for a power supply.

 

[WyomingKnott]

Hawkeye: Didn't USB 3.0 increase the available power? Yes, the OP should use a drive with a separate power supply, but...

USB 3.0 increased the power from 0.5 watts to 0.9 watts at a nominal 5 volts. Still pretty tight for a 3.5" HDD, at under 5 watts.

 

[Hawkeye22]

Hawkeye: Didn't USB 3.0 increase the available power? Yes, the OP should use a drive with a separate power supply, but...

USB 3.0 increased the power from 0.5 watts to 0.9 watts at a nominal 5 volts. Still pretty tight for a 3.5" HDD, at under 5 watts.

Yes they did. I wish they had boosted it just a bit more. You might be able to get away with using USB power alone, but as you stated, it will be tight. If the manufacturer provides a power adapter, then I assume it won't be able to draw enough power from the USB port.

If the OP is willing to trade off a 3.5" drive for a 2.5" drive, then he'll have more options available.

 

[WyomingKnott]

I've got two 2.5" USB 2.0 drives that require that g*d-awful Y cable to draw power from two USB ports. I usually plug them into a powered USB hub that I have that's way out of spec - it provides massive amounts of power if the drive tries to pull it.

 

[gggirlgeek]

Thank you all. This is what I thought.

I hate hunting for an extra power outlet but I want to put my old 3.5" drives to use so no choice. I've decided to go with both types of front ports though, since I found one for $49.99.

http://www.newegg.com/Product/Product.aspx?Item=11-147-159&SortField=0&SummaryType=0&Pagesize=10&PurchaseMark=&SelectedRating=3&VideoOnlyMark=False&VendorMark=&IsFeedbackTab=true&Keywords=%28keywords%29&Page=1#scrollFullInfo

 

[fzabkar]

A USB port provides power at +5V.

A 3.5" drive requires +5V and +12V power. I haven't heard of any external enclosure that steps up a +5V input to +12V. Plenty of +12V enclosures go the other way, though.

 

[gggirlgeek]

Thanks guys.

 

[WyomingKnott]

So many times I've wished that I had DC 5V and 12V outlets in my home office...

 

[gggirlgeek]

Best answer selected by gggirlgeek.