[PLUG] Accessing individual external hard drives in the same enclosure

[Tomas Kuchta]

Two USB devices are twice as fast only if you can connect them to two
separate root hubs in the PC.

I'd check this before being too optimistic:
a) do you have 2 root hubs - unlikely in a laptop without a dock or TB port.
b) Did you connect the devices to separate root hub ports physically?

Unless you have done a) and b) it is just by chance.

Tomas

On Sep 29, 2017 1:13 PM, "Keith Lofstrom" <keithl at kl-ic.com> wrote:

> On Thu, Sep 28, 2017 at 06:23:28PM -0700, Rich Shepard wrote:
> >   I have a HornetTek dual-bay external hard drive case (SATA II and USB 2
> > which are adequate for my needs).
>
> My guess is that the dual drive enclosure requires
> special windoze software to switch something in the
> controller chip in the drive.  By now, some obsessive
> Linux coder might have reverse engineered that and
> made a Linux driver for it.  That driver will be alpha
> code, unlikely to find it's way into a distro.
>
> But there's a good reason why nobody smart enough to
> write a driver would bother:
>
> A question you should ask is whether you mind losing two
> drives rather than one if the (presumably supercheap)
> HornetTek power supply fails, loses regulation and zaps
> the 5V drives with (say) unregulated 10 volt power?
>
> That is why an impulse-buy dual bay "drive toaster" sits
> in an unopened box on my shelf.  Partly because I was
> too lazy to return it, partly to remind me of unintended
> consequences discovered by subsequent contemplation.
>
> Running two separate enclosures costs a little more and
> may burn more power when both are operating, but burns
> less power when only one enclosure is powered at a time.
>
> If I need to make an operating-system-mediated drive-to-
> drive copy, two enclosures is twice as fast.  With low
> bandwidth USB2, that matters a lot.  So, the total
> energy per copy is less with two enclosures.
>
> Something to ponder.  Small acknowledged mistakes can
> forestall bigger ones.
>
> Keith
>
> --
> Keith Lofstrom          keithl at keithl.com
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