[gentoo-user] Re: [OT] Disappointing USB3 performance

[Grant Edwards]

On 2011-10-24, walt <w41ter@×××××.com> wrote:

> I just bought an add-on USB3 adapter and outboard USB3/sata docking
> station, and I've been comparing the performance with my old e-sata
> outboard docking station.  Not so good :(
>
> After getting some unreliable results with hdparm, I settled on
> copying one 3GB file from one partition of the outboard drive to
> another partition of the same drive.  These results are highly
> reproducible, and favor e-sata over USB3 by a large margin.
>
> Over at least six trials on each docking station I consistently get
> 105 seconds for USB and 84 seconds for e-sata, a 5:4 ratio in favor
> of e-sata.

Not surprising.  Did you expect that adding a gateway device to the
communication path and another protocol layer on top of SATA would
make things faster?

> I used the same hard disk and the same pci-e slot in the same
> minimally-loaded machine for all the runs, and got very consistent
> results every time.
>
> Basically, the USB3/sata docking station gets the same throughput as
> the older sata 1 drives connected to the onboard pci sata controller,
> which is still pretty respectable for an outboard drive, I think.

Yep, SATA performs the same as SATA. AFAIK, eSATA and SATA are
identical apart from the physical specs for the connector, a few minor
voltage level differences (to imporove noise tolerance), and hot-plug
support.

> So, has anyone out there done similar tests on USB3 drives yet?

There are disk drives that talk USB3 natively and aren't just using
USB<->SATA gateways?

-- 
Grant Edwards               grant.b.edwards        Yow! How many retured
                                  at               bricklayers from FLORIDA
                              gmail.com            are out purchasing PENCIL
                                                   SHARPENERS right NOW??