External harddrive (USB) Lacie (2.5") - Slow on the ONE SSD

Hi,
As the subject states, I tried hdtach on my newly bought Lacie 250gb 2.5" external hd.
On the One (SSD), with Vista Ultimate (vlite'd), 1.5Gb ram, I got a puny 19.5Mb/s (with both long and short bench).

On my stationary PC, I got 28Mb/s!

Why is the AAOne so slow on the USB? Ps. I tried both the ports on the left and right.
I also tried supplying extra power, via the power-usb cable.

I have a theory:
Is this due to the fact that the write-speed on the built-in ssd is so low, that it will limit the One's capability of benchmarking it's usb-ports?

My plan was fitting the hd inside the One, but if it really has that measly 19.5Mb/s limit, I think I'm better off buying a very fast SD card and use that for SWAP.