Download/write speed very slow

[subbia]

I bought a 1TB 2.5" usb 3.0, its attached over an USB 2.0 hub, and I'm getting this:

Code:

~# hdparm -Tt /dev/sda1

/dev/sda1:
Timing cached reads:     2 MB in 30.72 seconds =  66.68 kB/sec
Timing buffered disk reads:   2 MB in 28.44 seconds =  72.00 kB/sec

~# mount
/dev/sda1 on /mnt/ext type ext4 (rw,relatime,sync,data=ordered)

What could I look at?

Thanks in advance!

Cheers,
Dario