USB 3.0 hub question

[jkauff]

I have 8 USB 3.0 external hard drives, seven of them on a hub. The drives on the hub have slower transfer speeds than the one on a motherboard port, which is to be expected. However, when I recently added drive #8, all the hub drives suffered a significant slowdown.

Would I get better performance with fewer drives per hub? In other words, should I replace my 9-port hub with two 4-port hubs?

 

[BlueWeasel]

Are the drives USB powered (by the hub) or externally?

 

[corkyg]

Is the hub a 3.0 one? 3.5-in drives should be powered by their own sources. 2.5-in drives can be hub powered, but may require two ports with a Y connector. We need to know the specifics of the external drives.

With that many drives, you might consider a NAS rather than a hub.

 

[greenhawk]

in a ideal arrangement, (all drives self powered, hub is usb 3.0 ect) then it should only slow down when you are using multiple drives at a once. If using one drive or another then it should not be any noticeable slow down.

As to using two hubs instead of one large one, it might help, but it depends on the ports on your computer. Some computers use a internal hub to offer multiple USB3 ports so even with multiple hubs, they all still get restricted to a single USB3 controller, so no speed benefit for the same utilization you are currently using.

Also, USB was designed to use CPU power to work, so a slow CPU could cause issues in USB performance as well.

 

[jkauff]

Are the drives USB powered (by the hub) or externally?

Drives are all externally powered, as is the 3.0 hub.

 

[jkauff]

in a ideal arrangement, (all drives self powered, hub is usb 3.0 ect) then it should only slow down when you are using multiple drives at a once. If using one drive or another then it should not be any noticeable slow down.

These drives are all used for archives and backup of the archives. The slowdown is in drive-to-drive transfers, and it doesn't matter if I'm copying between the externals or from a SATA3 internal drive (the most common scenario).

I asked the question because of the global slowdown when I added the new drive. Can a hub be over-driven?