Hdds on usb hub

[kyrcy]

Is it "wise" to connect several external hdd drives (mostly 3.5" with power cables) on a usb2 or usb3 hub connected to a usb port and transfer data between them? Will transfer speed be the same if I connect each hdd to a usb port instead?

[theewizard]

while i have never performed a documented test
my observations are, that it is faster if each drive is on one of the PC's usb ports

no matter which method you choose the data has to go thru the pc,
read one, send to the other
it is Not drive to drive even when sharing a hub on the same port
and when using a hub and sharing a pc port, the pc is sending commands to the hub and the hub is switching back and forth between the drives
in most cases this is insignificant
but when coping many files or large files, it slows down the operation to have everything on the same PC port

[lingyi]

Is it "wise" to connect several external hdd drives (mostly 3.5" with power cables) on a usb2 or usb3 hub connected to a usb port and transfer data between them? Will transfer speed be the same if I connect each hdd to a usb port instead?

Devices connected to a USB hub share the bandwidth of the single USB port they're connected to, so it's best to put each HDD on a separate port on the motherboard. The catch is that some onboard USB ports are linked by an internal hub and share a single controller. Onboard USB 3.0 ports use a separate controller than onboard USB 2.0. You'll know if the port is sharing a controller because your transfer speed will drop significantly.

Use your USB 3.0 ports first, then 2.0. There's also ta limit on how much system resources are available for data transfer. For me, using one drive each on a USB 3.0 and a USB 2.0 port is overall transfer time is faster than running three or more drives at once.