Question about USB hubs.

I have several external hard drives.
Is it better to connect each hard drive to seperate USB sockets, or is
it OK to connect them all on a USB hub?

I've tested speeds of transferring between hard drives while connected
both to a hub.
I haven't noticed any difference.
(I didn't exactly do an exhuastive test transferring very large files.)

Thanks.


OM

OM wrote:
> I have several external hard drives.
> Is it better to connect each hard drive to seperate USB sockets, or is
> it OK to connect them all on a USB hub?
>
> I've tested speeds of transferring between hard drives while connected
> both to a hub.
> I haven't noticed any difference.
> (I didn't exactly do an exhuastive test transferring very large files.)

I'm a complete numpty with these things, but when I connected a hard
drive (in an external casing, of course) to USB I used to get situations
where it seemed to spontaneously dismount itself after some usage. It
happened to me with two separate drives on two separate machines, on two
separate OSs. I never did get to the bottom of it. In the end, I decided
that mounting the drives internally was the easiest way to go. Anyone
know what my trouble was likely to be?

On 30 Jul 2005 05:20:03 -0700, "OM" <om.newsgroup@gmail.com>
wrote:

>I have several external hard drives.
>Is it better to connect each hard drive to seperate USB sockets, or is
>it OK to connect them all on a USB hub?

It's OK, but that results in data transfer capped at the max
possible throughput of that single port which the hub is
attached to. Using the 2nd port on a USB socket would incur
the same throughput limitation but using any other, 2nd
port-pair per each drive would not.

>
>I've tested speeds of transferring between hard drives while connected
>both to a hub.
>I haven't noticed any difference.
>(I didn't exactly do an exhuastive test transferring very large files.)


USB is often much faster transferring large file(s) than
many small ones. In such cases you might see more gain. If
your hub is externally powered that might be a reason to
attach other devices since the typical external drive
enclosures are being powered by their own supply, and so
having the other devices attached to the hub would relieve
your system's USB power circuit from some of that burden.
Not that it's necessary for most low-current devices but
there are be a significant difference in current usage per
device.

> drive (in an external casing, of course) to USB I used to get situations
> where it seemed to spontaneously dismount itself after some usage. It
> happened to me with two separate drives on two separate machines, on two
> separate OSs. I never did get to the bottom of it.

I think 'the bottom of it' is the fact that Windows will turn off USB
devices that aren't in use.
If you go into device manager - USB controller - USB root hub (any of
them) - power managment tab, you can turn off this setting. It's on by
default.
--


"I don't cheat to survive. I cheat to LIVE!!"
- Alceryes




"Mark Carter" <me@privacy.net> wrote in message
news:42eb7760$0$18640$14726298@news.sunsite.dk...
> OM wrote:
>> I have several external hard drives.
>> Is it better to connect each hard drive to seperate USB sockets, or is
>> it OK to connect them all on a USB hub?
>>
>> I've tested speeds of transferring between hard drives while connected
>> both to a hub.
>> I haven't noticed any difference.
>> (I didn't exactly do an exhuastive test transferring very large files.)
>
> I'm a complete numpty with these things, but when I connected a hard drive
> (in an external casing, of course) to USB I used to get situations where
> it seemed to spontaneously dismount itself after some usage. It happened
> to me with two separate drives on two separate machines, on two separate
> OSs. I never did get to the bottom of it. In the end, I decided that
> mounting the drives internally was the easiest way to go. Anyone know what
> my trouble was likely to be?

"Mark Carter" <me@privacy.net> wrote in message
news:42eb7760$0$18640$14726298@news.sunsite.dk...
> OM wrote:
>> I have several external hard drives.
>> Is it better to connect each hard drive to seperate USB sockets, or is
>> it OK to connect them all on a USB hub?
>>
>> I've tested speeds of transferring between hard drives while connected
>> both to a hub.
>> I haven't noticed any difference.
>> (I didn't exactly do an exhuastive test transferring very large files.)
>
> I'm a complete numpty with these things, but when I connected a hard drive
> (in an external casing, of course) to USB I used to get situations where
> it seemed to spontaneously dismount itself after some usage. It happened
> to me with two separate drives on two separate machines, on two separate
> OSs. I never did get to the bottom of it. In the end, I decided that
> mounting the drives internally was the easiest way to go. Anyone know what
> my trouble was likely to be?

I read that it could be down to the power available to the USB hub, but as
someone else has posted more likely windows turning off unused devices.