Aharon said:
It has been long time since I built my last computer. In those days
SATA was not common on main boards, therefore I have no experience
whatsoever with SATA.
The case of the computer I am building now has a connection for eSATA.
The main board, GIGABYTE GA-H55M-S2H, has six internal SATA
connectors, labelled zero thru five. Does it matter to which of those
six the eSATA cable is connected? Is there any reason to prefer
connecting the eSATA cable to any specific SATA internal connector?
This main board also has an IDE internal connector, For the time being
I intend to use only my current IDE hard drive to be connected to this
connector. I am planning to add SATA hard drives later.
Thanks in advance for any advice.
Well, first you might be interested in a port that supports AHCI
as a setting. AHCI includes in its feature set, support for hot
swapping, so the hard drive will be recognized when the cable is plugged
into the computer (sort of how USB works). Without a working hot swap driver,
you plug in the ESATA drive before you boot, so it can be detected during
the boot process. (Note that, AHCI is not the only way to get hot swap.
There have been SATA chips that supported hot swap before AHCI came along.
But with your Intel motherboard ports, AHCI is where it's at. The first
person to have working hot swap, was someone who broke the connector
on their hard drive, and noticed every time they held the broken
connector to the drive, it was detected
That's how they safely
retrieved all the files off the drive, before throwing it away.)
http://en.wikipedia.org/wiki/Ahci
An Intel motherboard, might split the ports into two groups. A group
of four ports, and a group of two ports. Sometimes the properties of
the ports are controlled separately. If you'd decided to use a
non-AHCI mode for your boot drive, and your boot OS was an older
OS (where it's hard to change the driver mode), then the easiest
thing might be to look at the port groupings in the BIOS, and
use a port on the other group, so you can change the mode without
affecting your ability to boot.
Now, I downloaded your manual, and it doesn't seem to separate the
six ports into groups. They all seem to be controlled by one
setting (AHCI or IDE). All I can say at this point is, either
you'll get lucky, and you built the system up with the thing set to
AHCI, or you'll be unlucky, and end up having to connect the drive
before the system boots. While Vista and Windows 7 make it relatively
easy to change disk modes (simply change one or more registry settings
to "re-arm" the OS), an older OS like WinXP makes it in your
best interest, to get it right from the very beginning.
*******
The second issue, is a relatively minor one. SATA and ESATA have
slightly different electrical requirements. Basically, the ESATA
launch amplitude and receiver sensitivity, are designed so a longer
cable will work. Either the motherboard maker leaves all the ports
electrically in an ESATA mode all the time, and a longer cable works
anyway, or, the alternative, is you connect an ESATA interface, and
only a short (1 meter) cable works. Now, I don't own any ESATA enclosures,
but if I was buying one, I'd have no incentive to own a 2 meter cable,
and would simply buy a short cable. By investing in a short ESATA cable,
it saves me from having to worry about my receive sensitivity etc.
http://en.wikipedia.org/wiki/Esata#eSATA
Other issues, include all the variations provided by manufacturers.
Some turkeys, in years past, provided ordinary SATA ports on an adapter
plate, and pretended that was ESATA. A real ESATA connector has more
metal in the housing, and a real ESATA connector can take something like
5000 insertions and removals. The days of using the wrong connector are
probably behind us. (There was even one product, that didn't even use
a SATA or ESATA connector for the external drive!)
There is a new version of ESATA connector, called ESATAp, and it's backward
compatible with the old (metal) connector. The idea is, when a computer
has an ESATAp connector, the computer can send power to the hard drive.
If you had an ESATAp assembly, and an ESATAp hard drive housing, you'd no
longer need an external power adapter. But the odds of that working out for you
at the moment are pretty slim. Again, defensive purchasing says to buy
a traditional ESATA enclosure with its own adapter, as that is always
going to work. ESATAp would have been fine, if some genius had thought
of it from Day One. But introducing it now isn't very useful (customers
will have a mix of equipment, and never know what to expect).
HTH,
Paul
