General USB bandwidth limitation for harddisk

This is merely serving as information for those who might have noticed that their USB harddisk is showing unstable performance.

I noticed in a thread on the Sony board that a person was experiencing this and decided to run a couple of tests myself on my ThinkPad X61.

So I connected the notebook to the X6 UltraBase with the DVD burner plugged in, and a mouse and USB broadband modem connected as well. I then connected my external USB harddisk and ran HD Tune. The maximum it could get up to was about 18 MB/s (it was hovering between 17.4 and 17.8 MB/s).

I then un-docked from the docking station and connected the USB harddisk directly to my notebook. Suddenly it was showing results between 26.4 MB/s minimum and 26.8 MB/s maximum.

I ran the same test on a different notebook and experience the same phenomenon, albeit showing slightly lower scores.

So in case anyone wants to transfer large amounts of data between their USB harddisk and their notebook, I would suggest you to first unplug the notebook from your docking station, detach all USB bandwidth heavy items - and then plug in the USB harddisk.

 

Thanks for the info, this is good to know.

 

I second that. Useful info. Many thanks!

 

Glad to be of service. I just tested the above by transferring some large amounts of data and it did in fact make a difference in real life. So once again: for best transfer performance unplug all USB heavy items.

 

Very helpful thanks!