If you have multiple hard drives connected to a USB hub, does copied data move through the computer first or directly through the USB hub itself? Today’s SuperUser Q&A post has the answers to a curious reader’s questions.
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
Photo courtesy of itBox24 (Flickr).
The Question
SuperUser reader IAmJulianAcosta wants to know if two USB hub connected drives could transfer data directly via the USB hub and completely bypass the computer:
What route will the data take when being copied from one USB drive to the other?
The Answer
SuperUser contributors lzam, Luu Vinh Phuc, and fixer1234 have the answer for us. First up, lzam:
Followed by the answer from Luu Vinh Phuc:
If anything, having two hard-drives connected to the same USB hub might slow things down. If you have multiple devices connected to the hub, they have to share the bandwidth.
And our final answer from fixer1234:
Assuming that you can connect the two drives like that, how will they know which files and/or folders you want to copy? How will they know which drive to copy from and will they overwrite duplicated files? How will they behave if the drives are full?
Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.
There is no performance benefit and there may be a performance detriment. The USB hub itself is connected to the computer through a USB connection, so everything connected to the USB hub has to share the bandwidth of that connection. Hard-drives can consume a lot of the USB hub’s bandwidth and affect the performance of other devices attached to the USB hub. You generally do not want to connect hard-drives through a USB hub at all because of that.
