[OT] Re: Typical SATA to SATA rates

[Nifty Ubuntu]

On Thu, Oct 15, 2009 at 11:27 AM, Keith Clark
<keithclark at k-wbookworm.com> wrote:
> On Thu, 2009-10-15 at 11:11 -0400, Ray Leventhal wrote:
>> Keith Clark wrote:
>> > I am using Simple Backup Suite to backup one SATA drive to an identical
>> > SATA drive on the same computer.  I only seem to be able to get speeds
>> > of around 29 Mb/s.  Doesn't this seem to be a bit slow?  Is there
>> > anything I can change to speed this up?
>> >
>> > Keith
>> >
>> SATA bus transfers are typically in the 3GiB/s rate...so yes, that's a
>> bit slow.  Are both drives on the same bus?
>>
>> -R
>
> Well, I decided to open the machine physically and there is only one
> SATA drive!  The two I am using are EIDE.  What should typical speeds be
> between these two drives now?  There is only one bus on this
> motherboard.
>
> Keith

Do review the disk specifications.  Look for two things
   -  interface data rate
   -  controller to media data rate.

The interface controller rate will often be many times faster
than the controller to media transfer rate.   The interface
data rate permits some overlap in time for two devices
on the same bus.

All in all 29 Mb/s sounds correct you are going to limit out
on one of "read" or "write" data rates minus a shared bus
interaction overhead.