External HDDs (Question)

[DanF]

As far as I know, you always need to directly connect the external HDDs to the main power, unless the HDD is below 160GB. Correct me if I'm wrong.

Yesterday I was chatting with a client of mine while doing some work on his system and asked for my opinion as regards to external HDDs, as he needs to get one himself. During the chat he told me about a retail shop owner who told him that it is possible to have the hard drive connected to two USB ports, instead of one, which eliminates the need of a power cable. At that point, I was confused and told my client that I'll be checking about this as I didn't know of this myself. All I know, and I've told him about this, is that I have an IDE/SATA to USB external device which I use for backups etc... and that it also has 2 USB connections, which you need to connect both in order for the HDD to work, and that you still have to use the power cable.

Can someone clarify this for me, please? Also, do notebook HDD differ from normal HDDs in terms of power usage, which means, do they require less energy?

Thanks

 

[iptech]

As far as I know, you always need to directly connect the external HDDs to the main power, unless the HDD is below 160GB. Correct me if I'm wrong.

Yesterday I was chatting with a client of mine while doing some work on his system and asked for my opinion as regards to external HDDs, as he needs to get one himself. During the chat he told me about a retail shop owner who told him that it is possible to have the hard drive connected to two USB ports, instead of one, which eliminates the need of a power cable. At that point, I was confused and told my client that I'll be checking about this as I didn't know of this myself. All I know, and I've told him about this, is that I have an IDE/SATA to USB external device which I use for backups etc... and that it also has 2 USB connections, which you need to connect both in order for the HDD to work, and that you still have to use the power cable.

Can someone clarify this for me, please? Also, do notebook HDD differ from normal HDDs in terms of power usage, which means, do they require less energy?

Thanks

External drives that use 3.5" HDD will need an external power supply, external drives that use 2.5" drives can usually be powered from the USB hub although on some systems they may need top draw power from two USB sockets (yet only transfer data via one) hence they two USB 'A' connectors. On most modern PCs and laptops with USB 2 hubs you do not need to use the power from two ports, one will suffice - the secondary power draw-off cable can be left disconnected. Alternatively many 2.5" drives allow power to be provided by a separate power supply instead of drawing all power from the USB hub.

 

[Daifne]

I have a couple of 2.5 externals that came with what I call Y connectors. I have only had to use both ports with them on systems that had USB 1. USB 2 seems to be able to handle them with just one connection.

 

[iisjman07]

Laptop drives will usually run on just one USB power source because they use less power (because the motor spins slower), but it's not uncommon for larger 3.5" to require two USB ports to gather enough power...