another question about usb power

white88enochian

this is not related to the other post


why does an external 2.5 sata need 2 usb ports to run on a netbook or old laptop but on a desktop it only needs one

oh and for some reason now it wont work on the laptop or netbook kinda like its being shorted out

the first question always happened even before it stoped working on netbook

Daktologist

Its because the usb ports cannot provide the current required for it to run. From memory the newer usb port standard allows for 1 amp where the older standard allows for only half that (500 mA). using two 500 mA ports in parallel allows for 1A to be available for the hdd to work.

chippy

^ this

Unknown

Wow, I never actually knew the reason for HDD's always having a cable with 2 USB heads on it. So, what happens if you plug both USB's into newer, 1A USB ports? Will it be damaging at all?

Daktologist

trx100 wrote: »

So, what happens if you plug both USB's into newer, 1A USB ports? Will it be damaging at all?

Nothing will be damaged, It will just have access to more current.

Unknown

Does having access to more current make any differences? (Speed of moving data, reliability, etc)

Sorry for the dumb questions, I'm a total newbie when it comes to electronics.

Daktologist

trx100 wrote: »

Does having access to more current make any differences? (Speed of moving data, reliability, etc)

Sorry for the dumb questions, I'm a total newbie when it comes to electronics.

All good mang. Basically its the equivalent of plugging a table lamp into a welder socket, sure it could draw 32 amps if it wanted to but it will only draw the same amount of current as if it were plugged into a 10 A household outlet. Makes no difference what so ever.

white88enochian

ty ,